U.S. patent application number 11/280931 was filed with the patent office on 2006-04-13 for flexible automated connection to virtual private networks.
Invention is credited to Yihsiu Chen, Mark Jeffrey Foladare, Shelley B. Goldman, Thomas Joseph Killian, Norman Loren Schryer, Kevin Stone, Roy Philip Weber.
Application Number | 20060080441 11/280931 |
Document ID | / |
Family ID | 25429700 |
Filed Date | 2006-04-13 |
United States Patent
Application |
20060080441 |
Kind Code |
A1 |
Chen; Yihsiu ; et
al. |
April 13, 2006 |
Flexible automated connection to virtual private networks
Abstract
A network interface unit is provided for use intermediate a LAN
and a public or private network, or a combination of both, for
establishing secure links to a VPN gateway. Login by a LAN client
with the network interface unit, addressing, authentication, and
other configuration operations achieved using a web page-based GUI
are applied in establishing tunnels from LAN clients to desired VPN
destinations. Illustrative network interface units include a DHCP
server and provide encryption-decryption and
encapsulation-decapsulation of data packets for communication with
VPN nodes. Configuration and connection of a client are further
enhanced by a built-in DNS server and other functional servers to
provide a high degree of autonomy in establishing connections to a
desired VPN gateway via an ISP or other public and/or private
network links to. The interface unit then performs required
authentication exchanges, and required encryption key
exchanges.
Inventors: |
Chen; Yihsiu; (Middletown,
NJ) ; Foladare; Mark Jeffrey; (East Brunswick,
NJ) ; Goldman; Shelley B.; (East Brunswick, NJ)
; Killian; Thomas Joseph; (Westfield, NJ) ;
Schryer; Norman Loren; (New Providence, NJ) ; Stone;
Kevin; (Fair Haven, NJ) ; Weber; Roy Philip;
(Bridgewater, NJ) |
Correspondence
Address: |
AT&T CORP.
P.O. BOX 4110
MIDDLETOWN
NJ
07748
US
|
Family ID: |
25429700 |
Appl. No.: |
11/280931 |
Filed: |
November 16, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09911061 |
Jul 23, 2001 |
|
|
|
11280931 |
Nov 16, 2005 |
|
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Current U.S.
Class: |
709/225 |
Current CPC
Class: |
H04L 63/0272 20130101;
H04L 63/0428 20130101; H04L 12/4675 20130101; H04L 12/4641
20130101; H04L 63/083 20130101; H04L 63/0227 20130101 |
Class at
Publication: |
709/225 |
International
Class: |
G06F 15/173 20060101
G06F015/173 |
Claims
1. A method performed at a network interface unit (NIU) for
communicating data packets over a non-secure network between client
devices on a local area network (LAN) and an access node for a
secure virtual private network (VPN) comprising authenticating at
least one of said client devices seeking to access said VPN,
thereby establishing at least one authenticated client device,
sending configuration information from a configuration server at
said NIU to said authenticated client devices, sending at least one
menu from a GUI server at said NIU to authenticated client devices,
receiving at least a first message reflecting at least one
selection at at least one of said authenticated client devices from
said at least one menu, and means for accessing said non-secure
network using information in said at least a first message, and
establishing a secure connection between said non-secure network
and said access node using a security server at said NIU.
2. The method of claim 1 wherein said configuration information for
each authenticated client device comprises information received on
behalf of each of said client devices upon an initial
authenticating of respective ones of said client devices.
3. The method of claim 1 wherein said authenticating comprises
sending a GUI page to each client device seeking access to said
VPN, said GUI page soliciting authentication information, and
receiving authentication information from client devices seeking
access to said VPN, and authenticating said at least one client
device seeking access to said VPN when received authentication
information bears a predetermined relationship to information
stored at said NIU for respective ones of said client devices.
4. The method of claim 1 further comprising storing a plurality of
web pages for use by said GUI server.
5. The method of claim 1 wherein said at least one menu comprises a
main menu comprising selections corresponding to predefined access
connections to said non-secure network.
6. The method of claim 5 wherein said first message comprises
information indicating a selection of a predefined access
connection to said non-secure network.
7. The method of claim 6 wherein said predefined access connection
is a dial-up connection and said accessing of said non-secure
network is accomplished using configuration information
corresponding to said dial-up connection.
8. The method of claim 5 wherein said first message comprises
information indicating a selection of a predefined type of access
connection to said non-secure network.
9. The method of claim 8 further comprising sending a second menu
from said GUI server to a client device seeking access to said VPN
in response to said first message, said second menu including
information regarding at least one connection to said non-secure
network, said second menu including only information for
connections of only said predefined type.
10. The method of claim 9 wherein said predefined type of
connection is a dial-up connection.
11. The method of claim 9 wherein said predefined type of
connection is a network connection employing a fixed IP
address.
12. The method of claim 9 wherein said predefined type of
connection is a network connection employing a temporary IP
address.
13. The method of claim 12 further comprising accessing a DHCP
server at said NIU to obtain said temporary IP address.
14. The method of claim 12 further comprising accessing a DHCP
server in said non-secure network to obtain said temporary IP
address, said accessing of said DHCP server comprising employing a
DHCP client at said NIU to access said DHCP server in said
non-secure network.
15. The method of claim 9 wherein said predefined type of
connection is a network connection employing a fixed point-to-point
over Ethernet (PPPOE) address.
16. The method of claim 5 wherein said first message comprises
information indicating a request for a new connection to said
non-secure network.
17. The method of claim 16 further comprising sending a form from
said GUI server to a client device seeking access to said VPN in
response to said first message, said form soliciting information
regarding said new connection.
18. The method of claim 17 wherein said new connection is a dial-up
connection, and said information solicited by said form comprises
dial-up information relating to said new connection.
19. The method of claim 18 wherein said new connection is a network
connection, and said information solicited by said form comprises
network information relating to said new connection.
20. The method of claim 16 further comprising storing information
received from a client device responding to said form, said
information being stored as configuration information associated
with said responding client device relating to a connection of an
indicated type.
21. The method of claim 20 wherein said storing configuration
information comprises storing configuration information in a
removable memory module.
22. A method practiced at a network interface unit (NIU) for
communicating data packets over a non-secure network between client
devices on at least one local area networl (LAN) and at least one
access node of a secure virtual private network (VPN), the method
comprising receiving data packets from said devices by way of said
LANs, multiplexing said data packets into at least one packet data
stream, modifying said packet data streams in a security server in
accordance with a secure communications protocol by encrypting
packets in said data streams and encapsulating resulting encrypted
packets, providing network destination address information from a
DNS server for at least selected ones of said data streams.
23. The method of claim 22 wherein said modifying said packet data
streams ona security server comprises modifying said packet streams
in an IPsec server.
24. The method of claim 23 further comprising receiving at least
one stream of data packets from said non-secure network, filtering
out packets in said streams received packets that are not from said
VPN network, said filtering being performed by a firewall in said
security server, modifying said packets in said at least one stream
by decrypting said packets in said at least one received data
stream and decapsulating resulting decrypted packets, said
decrypting and decapsulating being performed by said security
server, demultiplexing said at least one stream of received data
packets to form at least one demultiplexed stream of data packets
for delivery to said at least one LAN.
25. The method of claim 24 further comprising authenticating client
devices on said at least one LAN, and wherein packets from
authenticated client devices on said at least one LAN that are
received at said network interface device are processed as packets
received from said VPN.
26. A method for securely communicating data packets over a
non-secure network between client devices on a local area network
(LAN) and a secure network, the method performed at a network
interface unit (NIU) appearing as a device on said LAN, the method
comprising (1) authenticating at least one of said client devices
seeking to access said secure network, thereby establishing at
least one authenticated client device, (2) sending configuration
information from a configuration server in said NIU to at least one
of said at least one authenticated client device, thereby
establishing at least one configured client device, (3) in response
to a request from at least one configured client device to connect
to said secure network, providing destination address resolution
information from a Domain Name System (DNS) server in said NIU, (4)
establishing a secure VPN connection between said at least one
configured client device and an access node at an address provided
by said DNS server, said secure VPN connection using a security
server in said NIU.
27. The method of claim 26 wherein said NIU is a portable unit and
said method further comprises connecting said NIU as a device on
said LAN.
28. The method of claim 26 wherein said NIU comprises a memory for
storing programs for controlling said NIU and data comprising data
for configuring at least said client devices on said LAN.
29. The method of claim 26 wherein said NIU includes at least one
removable memory device for storing programs for controlling said
NIU.
30. The method of claim 26 wherein said NIU includes at least one
removable memory device for storing configuration information for
at least said client devices on said LAN.
31. The method of claim 28 wherein said memory stores data
comprising translation data for providing said destination address
resolution information from said DNS server.
Description
RELATED APPLICATIONS
[0001] The present application is related to concurrently filed
non-provisional application by the applicants of the present
application, which related application is entitled System for
Automated Connection to Virtual Private Networks, and is assigned
to the assignee of the present invention, and which related
application is hereby incorporated by reference as if set forth in
its entirety herein.
FIELD OF THE INVENTION
[0002] The present invention relates to data networks, and, more
particularly, to automated access to data networks. Still more
particularly, the present invention relates to flexible automated
access to virtual private networks based on selectable access
criteria.
BACKGROUND OF THE INVENTION
[0003] Recent years have witnessed a surge in popularity of the
Internet. Access and increased use by home users, small businesses,
large corporations, universities and government agencies continues
to increase at a rapid rate.
[0004] Generally speaking, the Internet may be considered as the
interconnection of a large number of local, regional or global
networks interconnected using one of several global backbone
communications routes, with access provided by Internet service
providers (ISPs) or direct network-to-network connection (typically
for large users). Access to ISP networks is typically accomplished
using the well-known Internet Protocol (IP) through ISP points of
presence (POPs) in many different locations around the country,
thus permitting customers to have local dial-in access or a short
leased-line access. After gaining access to an ISP users have
access to the Internet, usually through a hierarchy of local access
providers and other network service providers. Increasingly, access
is available through a variety of broadband access technologies,
such as "always-on" cable and DSL modems connected over CATV cable
facilities or local telephone lines at data rates many times higher
than dial-up telephone links.
[0005] Another aspect of evolving networking needs of corporate and
other data communications users relates to the mobility of
employees, customers and suppliers requiring access to headquarters
or branch locations of an enterprise. Home office and temporary
access to corporate networks, including access from hotels and
offices of customers, suppliers and others is of increasing
importance to many network users and operators.
[0006] Such widespread use and access, including temporary or
mobile access, has raised concerns by many for the security of
transmissions over the public links of the Internet. Large
corporations with extensive networking needs have in many cases
preferred private networks for their typically large volumes of
data to many different locations. It has proven relatively easier
to provide security measures for insuring the integrity and privacy
of communications between stations or nodes in private networks
using a variety of data checking and encryption technologies.
[0007] For example, secure private networks are typically protected
by firewalls that separate the private network from a public
network. Firewalls ordinarily provide some combination of packet
filtering, circuit gateway, and application gateway technology,
insulating the private network from unwanted communications with
the public network.
[0008] Encryption in private networks is illustratively performed
using an encryption algorithm using one or more encryption keys,
with the value of the key determing how the data is encrypted and
decrypted. So-called public-key encryption systems use a key pair
for each communicating entity. The key pair consists of an
encryption key and a decryption key. The two keys are formed such
that it is not feasible to generate the decryption key from the
encryption key. Further, in public-key cryptography, each entity
makes its encryption key public, while keeping its decryption key
secret. When sending a message to node A, for example, the
transmitting entity uses the public key of node A to encrypt the
message; the message can only be decrypted by node A using its
private key. Many other encryption algorithms are described in the
literature. See, for example B. Schneier, Applied
Cryptography--Protocols, Algorithms, and Source Code in C, John
Wiley and Sons, New York, 1994.
[0009] Information regarding encryption keys and the manner of
using them to encrypt data for a particular secure communications
session is referred to as key exchange material. Key exchange
material illustratively includes keys to be used and a time
duration for which each key is valid. Both end stations in an
end-to-end path must know key exchange material before encrypted
data can be exchanged in a secure communications session. The
manner of making key exchange material known to communicating
stations for a given secure communications session is referred to
as session key establishment.
[0010] Many of the integrity and privacy safeguards long employed
in private networks have not always been available in networks
involving at least some public network links. Yet, smaller users
and, increasingly, large users have sought techniques for safely
employing public networks to meet all or part of their
communications network needs. Among the techniques employed to
provide varying degrees of approximation to security advantages
available in private networks while employing public links are
so-called virtual private networks or VPNs.
[0011] VPNs provide secure communications between network nodes by
encapsulating and encrypting messages. Encapsulated messages are
said to traverse a tunnel in a public network, and are encapsulated
by a process of tunneling. Tunnels using encryption provide
protected communications between users at network nodes separated
by public network links, and may also be used to provide
communications among a selected or authorized subset of users in a
private network.
[0012] In a VPN, a tunnel endpoint is the point at which any
encryption/decryption and encapsulation/de-encapsulation (sometimes
called decapsulation) is provided in a tunneling process. In
existing systems, tunnel end points are predetermined network layer
addresses. The source network layer address in a received message
is used to determine the credentials of an entity that requests
establishment of a tunnel connection. For example, a tunnel server
uses the source network layer address to determine whether a
requested tunnel connection is authorized. The source network layer
address is also used to determine a cryptographic key or keys to be
used to decrypt received messages.
[0013] Existing tunneling processing is typically performed by
encapsulating encrypted network layer packets (also referred to as
frames) at the network layer. Such systems provide network layer
within network layer encapsulation of encrypted messages. Tunnels
in existing systems are typically between firewall nodes that have
statically allocated IP addresses. In such existing systems, the
statically allocated IP address of the firewall is the address of a
tunnel end point within the firewall. Existing systems that connect
local-area networks (LANs) fail to provide a tunnel that can
perform authorization for a node that must dynamically allocate its
network layer address. This is especially problematic for a user
wishing to establish a tunnel in a mobile computing environment for
which an ISP allocates a dynamic IP address.
[0014] U.S. Pat. No. 6,101,543 issued Aug. 8, 2000 to K. H. Alden,
et al., discloses techniques seeking to establish a tunnel using a
virtual or so-called pseudo network adapter. In particular, Alden,
et al., seeks to have a pseudo network adapter appear to the
communications protocol stack as a physical device for providing a
virtual private network having a dynamically determined end point
to support a user in a mobile computing environment. The pseudo
network adapter disclosed in Alden, et al. seeks to receive packets
from the communications protocol stack and pass received packets
back through the protocol stack either to a user or for
transmission.
[0015] An important IP layer security architecture and protocol for
use in networking over IP networks such as the Internet is
described in S. Kent and R. Atkinson, "Security Architecture for
the Internet Protocol," IETF Network Working Group Request for
Comments 2401, Nov. 1998. The so-called IPsec protocols and
processes described in that IETF document have proven useful in a
number of contexts.
[0016] Despite growing experience with connecting computers or
local networks to other networks, including the Internet, many
users experience difficulties in establishing reliable, secure
connections under a variety of circumstances. Such difficulties
arise, in part, because many configuration variables must be taken
into account, such as whether the connection is for a single
computer or for a local area network (LAN), whether a location is
to be identified by a dynamic or static IP address, as well as the
type of connection required. Thus, for example, a traveling
employee may require access to a corporate headquarters network
using a dial-up telephone line from a hotel, or a leased line
connection from a supplier location. Many home or home office users
will connect to the Internet through a dial-up line using an analog
modem, while others will employ cable or DSL modem links. Each
connection type and location may require specific configuration
information that can be daunting to frequent travelers and can
consume considerable time and effort even by those having
considerable networking skills.
[0017] Other factors that must be dealt with in establishing
connections from home, field office, hotel, and other mobile
locations (such as wireless links from the field) relate to network
address information to be employed for network, including Internet,
access. An IP (Internet protocol) address represents a
communications end point, but some network nodes, such as shared
computer facilities at a company location may have many users per
address or many addresses per user. A typical network node will be
identified by a unique 32-bit IP address of the form 101.100.2.2. A
router that directs information to various end hosts has an IP
address such as "101.100.2.1 ", where the last part will be a
unique number identifying end hosts connected to the router. For
example, for three hosts connected to such a router, these hosts
may have IP addresses of 101.100.2.2, 101.100.2.3, and
101.100.2.4.
[0018] While occasional users may only require a temporary or
dynamic address for each session, or transaction, with the same
address being assigned to another user after the session or
transaction is complete, many network nodes, such as those
associated with a corporate host or network service provider
require one or more permanent or static IP addresses. With a static
IP address, authorized persons may direct traffic to or access
information available at the static IP address at any time.
[0019] As will be readily perceived, there are many complexities
and difficulties involved with connecting to and configuring a
computer or LAN for communication through the Internet. Moreover,
it will be appreciated that routers, including any at a customer
location or at an ISP, must be configured correctly. At an ISP, a
trained network operator is typically available for entering
configuration information into a router, including the IP address
of a customer, an account number, etc. Other configuration
information that must be entered includes telephone numbers to
dial, passwords, packet filter rules, LAN network information,
domain name information, e-mail configuration, compression
parameters and others.
[0020] Further, even when this is accomplished at an ISP, a
customer must be made aware of this information, to permit manual
entry of corresponding required information into networking
equipment at a user location, e.g., to configure a router. For any
but the simplest of connections, this process can prove tedious and
error-prone. Further, a mobile user will be required to reconfigure
his or her terminal or LAN for each new location, or access
facility. It will be appreciated that connecting a LAN can be
considerably more difficult than connecting a single computer node
(host or client), as networked components may require specification
of a variety of specific configuration parameters. Thus, parameters
for network components, e.g, routers, firewalls, DNS servers and
DHCP servers, and security mechanisms, must all be set correctly
before the LAN can successfully communicate with the Internet.
[0021] As noted above, secure links present additional
configuration and setup requirements, including, in appropriate
cases, key exchange material and other tunnel configuration
information. In prior work reported by some present inventors, a
network adaptor and configuration procedure was employed that
facilitates establishment of secure VPN tunnels, illustratively
using an IPsec protocol, for a range of applications and uses. See,
J. S. Denker, et al., "Moat: a Virtual Private Network Appliance
and Services Platform," Proc. 1999 LISA XIII-Nov. 7-12, 1999,
Seattle.
[0022] From the foregoing it will be appreciated that automation of
the configuration and setup of network nodes, including IP LAN
network nodes, seeking to securely communicate over IP networks,
such as the Internet, is highly desirable. Such automated
configuration and setup of computers and other network elements is
especially desirable for mobile users. It is likewise desired that
a flexible access system and configuration process be provided for
configuring a computer system for communication over IP
networks.
SUMMARY OF THE INVENTION
[0023] Limitations of the prior art are overcome and a technical
advance is made in accordance with the present invention,
illustrative embodiments of which are described below.
[0024] In accordance with aspects of one illustrative embodiment, a
network interface unit is provided for use intermediate a LAN and a
public or private network, or a combination of both, for
establishing secure links to other nodes in a VPN. Upon connection
and login with the network interface unit, addressing,
authentication, and other configuration operations are applied in
establishing tunnels to desired VPN destinations.
[0025] An illustrative network interface unit includes a Dynamic
Host Configuration Protocol (DHCP) server, illustratively
accessible using a web browser running on a client machine seeking
access to VPN nodes. Encryption and encapsulation of data packets
for communication with remote nodes or selected other nodes on a
LAN to which the subject client machine is connected (collectively,
tunnel end points) provides the required secure data transfer.
[0026] Configuration of a client machine for use with illustrative
embodiments of the present inventive network interface unit is
rapidly achieved by logging on to the network interface unit, e.g.,
employing a web browser, and specifying the nature of the
connection desired, including, as needed, the nature of the access
link (e.g., cable, dial-up, etc.), identification of a desired ISP
and destination. Information stored on the network interface unit
is then used to perform necessary login and other data access
procedures over links to an ISP and through public and/or private
network links to a desired VPN gateway or other access point,
including required authentication exchanges, and any required
encryption key exchanges.
[0027] Advantageously, illustrative embodiments of the present
inventive network interface unit present a uniform graphical user
interface (GUI) for pre-specifying desired types of connections,
ISP information and target VPNs. Moreover, using other aspects of
the GUI, a user's client machine is quickly and efficiently
configured to establish the desired secure tunnel to the target
VPN, with the user experiencing a uniform interface for a variety
of access circumstances..
[0028] It proves advantageous in some illustrative embodiments to
employ readily available components and streamlined storage and
processing to effect the configuring and establishment of secure
links. In some embodiments, some or all inventive network interface
unit functions will be incorporated in a client machine (e.g.,
personal computer), or in a dial-up, cable, DSL or other modem, or
in a LAN hub, switch, router or other network element connecting
client machines to an ISP or otherwise connecting a client machine
(directly or indirectly) to one or more public network links.
[0029] Aspects of the present inventive network interface unit and
its use include methods for entering use and configuration
information into an interface unit database, as well as extraction
and application of configuration information to client machines and
subsequent secure connection to desired VPNs.
BRIEF DESCRIPTION OF THE DRAWING
[0030] The above-summarized invention will be more fully understood
upon consideration of the following detailed description and the
attached drawing wherein:
[0031] FIG. 1 shows an illustrative prior art network arrangement
for establishing a link between an illustrative home office LAN and
a corporate network.
[0032] FIG. 2 shows an illustrative network arrangement for
establishing a secure link between the illustrative home office LAN
and corporate network of FIG. 1 using prior VPN arrangements.
[0033] FIG. 3 shows illustrative extensions to the network of FIG.
2 in accordance with aspects of the present invention wherein a
variety of access modes are served from a common network
interface.
[0034] FIG. 4 shows more detailed aspects of the organization of
the network interface unit of FIG. 3.
[0035] FIG. 5 shows illustrative content of a database or table
structure for memory elements shown in the network interface unit
of FIG. 4.
[0036] FIG. 6 is a flowchart showing illustrative client
configuration and link establishment employing the network
interface unit of FIG. 4.
[0037] FIG. 7 shows an illustrative login web page presented at a
user computer using a web browser for accessing a network interface
unit running a GUI server, this at a time when the user is seeking
to establish a secure link to a VPN.
[0038] FIG. 8 is a web page presented by a GUI server running at a
network interface unit to a user after login to the network
interface unit when a connection is to be specified.
[0039] FIG. 9 is a web page presented by a GUI server running at a
network interface unit to a user when a specified standard dial-up
connection link is to be edited.
[0040] FIG. 10 is a web page presented by a GUI server running at a
network interface unit to a user when a customized dial-up
connection link is selected at the screen of FIG. 8.
[0041] FIG. 11 shows a main menu page presented by a GUI server
running at a network interface unit at a time when a network
connection may be selected or newly specified.
[0042] FIG. 12 shows a screen that is presented by GUI server 450
upon selection of the DHCP option at the main menu of FIG. 8
[0043] FIG. 13 is a web page presented by a GUI server running at a
network interface unit to a user for selecting a desired network
service.
[0044] FIG. 14 is a screen presented when a new connection is
requested at main menu screen.
[0045] FIG. 15 is a web page presented by a GUI server running at a
network interface unit to a user when the user wishes to edit a
dial-up connection previously specified.
[0046] FIG. 16 is a web page presented by a GUI server running at a
network interface unit to a user when the user wishes to edit a
specified DHCP connection.
DETAILED DESCRIPTION
[0047] The following detailed description and accompanying drawing
figures depict illustrative embodiments of the present invention.
Those skilled in the art will discern alternative system and method
embodiments within the spirit of the present invention, and within
the scope of the attached claims, from consideration of the present
inventive teachings.
[0048] FIG. 1 shows an overall view of an illustrative LAN (e.g.,
home-office or telecommuter LAN) 101 as physically connected
through the Internet to a corporate headquarters (or main, or other
substantial secured network LAN node), 197. LAN 197 is shown having
a firewall 195 for receiving and appropriately filtering packets in
accordance with a predetermined security plan. Security Portal 190
provides encryption and decryption services for received authorized
packets, as well as encapsulation and de-encapsulation of received
packets, as is well known in the art. Hosts 1 and 2 provide
illustrative sources and sinks for information passing through
firewall 195.
[0049] Illustrative user LAN 101 is shown having an illustrative
assortment of user client computers and other facilities 104-107
and 110. Microsoft PC 104 represents a typical personal computer
client running applications under one of the Microsoft Windows
versions, while MAC 105 represents an illustrative Apple computer
client running applications under Apple's proprietary operating
system. Block 106 represents yet another client computer, this one
running one of the many variants of the UNIX operating system,
e.g., Linux, and applications compatible with that environment.
Peripherals, such as printer 107 and other clients are also shown
connected to LAN 101, as is well known in the art.
[0050] LAN 101 and illustrative clients connected thereto are shown
connected through network interface unit 102 and, for the
illustrative case of case of CATV (cable) access to the Internet, a
cable modem 103. (For illustrative context, another cable modem 120
serving a neighbor of the user at LAN 101 is included in FIG. 1 as
being connected on neighborhood cable 130 along with user's cable
modem 103.) Finally, representative Internet routers 140, 150 and
180 are shown providing links through the Internet, though other
network elements (not shown) may be included in the path from LAN
101 to LAN 197.
[0051] By way of illustration a path from router 150 is shown to a
World Wide Web host 160, while block 170 represents illustrative
ones of the many available Internet sites that may be accessible
through (generally unprotected) links from LAN 101. Finally, as
representative of the many security threats to communications over
the Internet and other public networks, FIG. 1 shows a block 175
labeled threats. The latter category of public network perils
includes, by way of example, monitoring nodes and agents seeking to
extract information passing between users without authorization by
such communicating users, as well as unauthorized access to nodes,
such as LAN 101. Inventive structure and operational features of
network interface units 102 acting in cooperation with other
elements of the illustrative LAN-to-LAN network provide apparatus
and methods for foiling attempts by threats represented by block
175. Such structures and operational features and methods will be
described more fully in the sequel.
[0052] FIG. 2 shows network interface unit 202 logically connected
through a tunnel 215 in the Internet to security portal 290
corresponding to portal 190 in FIG. 1. Thus, in accordance with
another aspect of the present invention firewall,
encryption/decryption, encapsulation/de-encapsulation and other
well-known VPN functions are performed through cooperation of
interface network unit 202 and security portal 290. Further,
inventive structures and functions of network interface unit 202
provide additional, enhanced services and processes to serve
clients at LAN 201 and other user locations, whether served by a
fixed or temporary network address.
[0053] FIG. 3 shows an elaboration of links from user LAN 301 to
LAN 397 interconnecting hosts 398 and 399 through firewall 395
using the services of security portal 390. In particular, access to
the Internet through illustrative neighborhood cable 130 (and 230
in FIG. 2) is elaborated to show a number and variety of access
links and methods, including (as before) cable modem 303 connected
to the Internet via cable ISP 323. However, the links from LAN 301
to Internet 350 in FIG. 3 by way of network interface unit 302 are
now shown to include wireless modem 311 (via wireless ISP 321),
dial-up modem 312 (via dial-up ISP 322), DSL modem 314 (via DSL ISP
324) and private line interface 315 (via private line 325). As will
be appreciated, each of these modems, interfaces, ISPs and
(private) lines, and services provided through them, are
characterized by certain addressing and operating parameters that
require configuration to coordinate with operations of the ISPs,
backbone Internet operations and destination node characteristics
(e.g., those of LAN 397).
[0054] Network interface unit 302 is advantageously adapted to
provide necessary configuration and operating control of secure
links from illustrative LAN 301 and user-selected destination
nodes, such as LAN 397. Of course, LAN 301 may not include all of
the client operations shown in FIG. 3, or more than one LAN may be
connected through network interface unit 302 to appropriately
configure and control the secure operation of whatever clients
require VPN services over the Internet (350) or other IP-based
network including public-network links.
[0055] FIG. 4 shows in more detail functions advantageously
available at network interface unit 302, which network interface
unit and operation thereof will now be described in greater
detail.
[0056] In overall organization, the network interface unit shown in
FIG. 4 includes a plurality of input ports 401-i, i=1, 2, . . . , N
transmitting and receiving data to/from respective client devices,
such as those shown in FIGS. 1-3, having illustrative standard
RJ-11 or RJ-45 connectors. Other particular connectors will be used
as appropriate to user needs. Correspondingly, ports 421-j, j=1, .
. . , N1, 422-k, k=1, 2, . . . , N2, and 423-1, 1=1, 2, . . . , N3,
with each grouping of ports illustratively representing RJ-11,
RJ-45, and one or another variety of personal computer serial
ports, respectively. One representative additional port, USB port
424 is also shown in FIG. 4. Other particular connection
arrangements and formats will be used as requirements may
dictate.
[0057] Input unit 410 in FIG. 4 multiplexes/demultiplexes (performs
mux/demux operations on) data passing from/to client devices
connected through ports 401-i, to output unit 420, which provides
similar multiplexing/demultiplexing functions with respect to data
passing through ports 421-j, 422-k, and 423-l and USB port 424.
(Input unit 410 and output unit 420 are arbitrarily referred to as
input or output units, though both units are bidirectional data
handlers. It sometimes proves convenient to identify input unit 410
and its associated ports as client-side unit and ports, while
referring to output unit 420 and its associated ports as wild-side
unit and ports).
[0058] In addition to standard buffering operations to accommodate
different or varying data rates, buffer-PAD unit 430 in FIG. 4
performs encapsulation and de-encapsulation (decapsulation) of IP
packets passing in each direction through IPsec tunnels in
accordance with IETF RFC 2406. Also, buffer-PAD 430 performs NAT
transformations in cooperation with NAT server 445, including
transformations on packets that are not routed through a tunnel for
policy reasons. See, for example, IETF RFC 1631. Packets in either
direction are susceptible of being dropped if they violate firewall
rules.
[0059] Controller 440 in FIG. 4 operates under program control,
including, illustratively, the well-known Linux operating system
and a variety of control programs (all stored in memory unit 475)
advantageously used in realizing, organizing and controlling
operation of the several functional units of the network interface
unit of FIG. 4. These functional units interact with users at
client devices (through ports 401-i) primarily during client setup
and configuration, illustratively using imbedded GUI server 450.
More particularly, as will be described below in connection with
FIGS. A-J, users logging-in to establish connections over a VPN are
presented with standard web page formats on client machines with
which connection and destination information is readily specified
or selected using web browser functionality on client computers.
These web pages are provided by GUI server 450 running at the
network interface unit of FIG. 4, which GUI server is of a
well-known design in widespread use for a range of web server
applications. Once configured, client computers (and other client
devices) send and receive packets under the overall control of
controller 440 acting in cooperation with the various (preferably
software-implemented) functional units to be described further
below.
[0060] In one aspect, controller 440 interacts with configuration
server 470 to receive and store configuration information. Such
configuration information is advantageously maintained and updated
in memory 475, and retrieved during configuration setup operations
through memory controller 480 under the overall control of
controller 440. Memory 475 is advantageously organized into one or
more separate memory elements. Flash memory 485 and bulk memory 490
are shown by way of illustration in FIG. 4, but any convenient,
appropriately sized memory device may be used--as will be
recognized by those skilled in the art. Because of the modest
memory requirements of many implementations of the network
interface unit of FIG. 4, it will advantageous to rely primarily on
removable memory devices, such as flash memory unit 485 shown in
FIG. 4.
[0061] Other functional elements served by memory 475 that operate
under the overall direction of controller 440 include GUI server
450 for providing web pages to users at client terminals 401-i
having appropriate browser software and display functions (such as
those available in personal computers, handheld computers, or
cell-phones capable of running web browsers or mini-browsers). When
employing standard personal computer web browsers, such as those
available from Netscape or Microsoft, client machines merely
interact, e.g., entering or selecting data associated with
predefined web page fields, as is well known in the art. Examples
of such interactions will be presented below.
[0062] When particular client devices on LAN 301 in FIG. 3 are not
capable of running a suitable GUI client application (such as a web
browser) for interacting with GUI server 450, it proves
advantageous to have another device, such as a personal computer
that is capable of executing a compatible GUI client application
may act on behalf of the client device not having such GUI client
application. While web browsers are described as suitable for
interaction with GUI server 450, other particular GUI servers and
compatible clients will be used in particular contexts and
applications of present inventive principles. In one preferred
embodiment of the present invention, a single GUI-client-enabled
client device on LAN 301 will login and authenticate with network
interface unit 302 on behalf of all devices on the LAN for purposes
of establishing appropriate tunnels to other locations on one or
more VPNs. Thus, once access to network interface unit 302 is
granted for a device (such as a personal computer) on a client LAN,
such as 301 in FIG. 3, all devices on that LAN are advantageously
configured.
[0063] By way of illustration of the use of cell phone-based
mini-browser interaction with GUI server 415, an Ericsson model
R280LX cell phone (with add-on data port, including a wireless
modem, represented FIG. 3 by wireless mode 311) will illustratively
employ one of several micro-browser cards to display and receive
information useful in specifying and selecting communications
access and destination information while connected to the network
interface unit of FIG. 4. User text input (and user-defined soft
keys available as a feature of the illustrative Ericsson cell
phone) will likewise be used to direct setup and operation of
secure data communications from a data source connected through a
cell-phone data port. In other client machines graphical styli,
touch-sensitive screens and other user inputs will be used, as
appropriate to particular circumstances.
[0064] Other control functionality and browser/GUI-server
interaction in executing particular user-level applications will be
readily implemented using any of a variety of scripts and applets,
e.g., coded in the well-known Java language and running at cell
phones (and other wireless clients) in coordination with GUI server
450. A variety of application tools are available, e.g., those from
Sun Microsystems in support of JAVA applications generally, and,
more particularly, for wireless applications using Sun's Java 2
Micro Edition (J2ME). Further application development support is
available from companies such as Lutris Technologies, which offers
its Enhydra XML- and Java-based server (including Lutris' i-mode
microbrowser) and other tools in support of wireless applications.
Lutris also offers tools promoting use of J2ME to create
applications for Motorola iDEN and other handsets. See, for
example, http://www.lutris.com.
[0065] IPsec server 460 cooperates with controller 440 to apply
desired encryption/decryption and encapsulation/de-encapsulation
operations required by user or VPN system controls. Appropriate
communications parameter values are provided to IPsec server 460
for communications between particular user clients and particular
network (ISP, destination host, and other) elements during
configuration setup. Encryption keys and other key exchange
material is likewise provided as part of configuration setup. While
various implementations of IPsec (IP security) software are
available, one software implementation appropriate for the Linux
environment is the so-called FreeS/WAN implementation available for
download at http://www.freeswan.org/intro.html. While this package
advantageously runs under the Linux operating system illustratively
employed by the network interface unit of FIG. 4, other IPsec
implementations are available for use in a variety of contexts and
environments.
[0066] IPsec uses strong cryptography to provide both
authentication and encryption services. Authentication ensures that
packets are from the right sender and have not been altered in
transit, while encryption prevents unauthorized reading of packet
contents. These services provided by IPsec support the desired
secure tunnels through untrusted (non-secure) networks, thereby
forming the desired VPN link. As note above, all data passing
through the untrusted net is encrypted by one IPsec-enabled network
node and decrypted by another IPsec-enabled node at the other end
of the link. In the examples of FIGS. 3 and 4, the illustrative
network interface unit of FIG. 4 (302 in FIG. 3) provides IPsec
processing, while complementary IPsec processing is performed at
security portal 390 in FIG. 3.
[0067] NAT server 445 shown in FIG. 4 cooperates with controller
440 to optionally provide network address translation to packets
received on client-side input unit 410 for the case of packets
being sent to parts of the Internet not included in a private LAN
such as LAN 397 in FIG. 3. Such packets are effectively masqueraded
as coming from an address belonging to wild-side output unit 420, a
technique known as split-tunneling that is well known in the art.
NAT server 445 also applies inverse operations to augment packets
received from unit 420 to permit reception by the proper client
device, all as is well known in IP networking. Use of NAT server
445 is advantageously a configuration option; a system
administrator may elect instead to have a private LAN, such as 397
in FIG. 3, handle outside traffic, e.g., through firewall 395.
[0068] DNS server 415 provides network address resolution for
destinations specified in other formats, and substitutes for access
to network-based DNS servers commonly used for non-secure
networking applications. Thus, by constraining client access to
only authorized destinations (as specified in the DNS server) a
further measure of security is assured. Of course, the authorized
destinations are those that have previously been authorized by
respective VPN operators, as augmented by user specification within
limits set by the network operators. While DNS server 415 stores
address resolution information in tables or other convenient form
in memory 475, it advantageously forwards requests for entries not
stored locally to a trusted server on the VPN, thus providing
security against so-called DNS spoofing.
[0069] Dynamic Host Configuration Protocol (DHCP) server 457 in
FIG. 4 provides a temporary or dynamic host network address (in the
context of FIGS. 3 and 4, a client network address in the sense of
being an address for a client device, such as a personal computer
on LAN 301 in FIG. 3). DHCP, defined in IETF RFC2131 and RFC2132,
and widely described, e.g., in N. Alcott, DHCP for Windows 2000,
O'Reilly, Sebastopol, Calif., 2001, permits reuse of IP addresses
when a client no longer needs the address. DHCP server 457 in FIG.
4 accesses a database of available IP addresses and related
configuration information (conveniently stored in memory 475) and
responds to requests from a client on illustrative LAN 301 for a
temporary network address. A pool of network addresses is
advantageously assigned to a VPN, and an authorized subset of such
assigned addresses is pre-stored in memory 475 for use by a
particular network adapter in the absence of any external network
connection. Thus, a network adapter of the form shown in FIG. 4
need not resort to an external DHCP server to commence
operation.
[0070] Having DNS and DHCP servers 435 and 457 operate without
recourse to hosts such as 398 and 399 (at the destination end of an
IPsec tunnel) in FIG. 3 in providing respective destination and
client addresses permits local or otherwise limited network
operation, even when WAN links to other network resources are not
available.
[0071] PPP client 458 provides connection facilities similar to
those provided by DHCP client 415, but does so for point-to-point
protocol connections. That is, IP addresses are allocated on an
as-needed basis and are commonly applied to short-term connections,
such as dial-up access to ISPs, and to some more permanent
connections--such as ADSL connections.
[0072] FIG. 5 provides a partial map of illustrative contents of
memory 475 for the network adapter unit of FIG. 4. In many
applications, especially those where size of the network interface
unit is important, it proves convenient to employ flash memory
elements 485 (or other detachable memory elements) for all of the
memory needs of the network interface unit. In any event, FIG. 5
shows, in a first memory portion, data components specifying device
type and identification information for client devices, e.g.,
personal computers, etc. Such information will describe relevant
aspects of the client device including, as appropriate, network
interface card (NIC) information for the client devices. It proves
convenient to also include, as needed, translated address
information assigned to devices by NAT server 445 in this portion
of memory 475.
[0073] A second portion of the memory map of FIG. 5 provides IP
configuration information for each of the client devices, including
assigned (permanent or temporary) IP addresses. Login, password,
telephone number and other information needed for dial-up
connections is also included in memory 475 as shown by the
corresponding memory map entry in FIG. 5. Encryption keys, other
key materials, as well as authentication and other security
information employed in operation of IPsec server 460 is
conveniently stored in the portion of memory map labeled tunnel
id.
[0074] GUI server web pages for display (via a web browsers
executing at client computers) and data input by users at clients
are stored in yet another portion of memory 475, as further
reflected in the memory map of FIG. 5. GUI information, including
any needed display element characteristics for each enrolled device
type is provided in the portion of memory 475 mapped as GUI info in
FIG. 5. Also shown in the memory map of FIG. 5 is a portion labeled
DNS information representing information used by DNS server 435 in
effecting needed address translations. DHCP address information
available for use by clients is stored in another illustrative
memory portion shown in FIG. 5, as is PPP information.
Illustrative Operation
[0075] FIG. 6 is a flowchart showing illustrative operations and
method steps in performing configuration and connection of client
devices, such as those shown by way of illustration in FIG. 3.
FIGS. 7-16 show illustrative web pages provided by GUI server 450
for use in setup and configuration of network clients in accordance
with illustrative embodiments of the present invention.
[0076] In FIG. 6, starting at 600, a scan is made (repetitively) to
test for the presence of clients on client-side inputs 401-i; a
test for client activity is then made at 610. If no client is
actively connected to a client-side input, or if a previously
active client becomes inactive (is effectively not present), all
active links (or, when a previously active client becomes inactive,
the previously active link) are taken down, as represented by 615
in FIG. 6.
[0077] If a client is found to be present at a client-side input by
the test at 610, a test is made at 620 to determine whether the
client is a new client. (In the following discussion, other
on-going links will be ignored to simplify description of steps for
a newly arrived client.) When a new client (or newly arrived or
returned client) is detected at 620, a login/authentication process
is performed by which a user at a client is determined to be a
person authorized to gain access to a VPN using an embodiment of
the present invention. As noted above, some embodiments of the
present invention provide that a single authorization for access
will grant access to all client devices on the LAN, so a presence
on the LAN will give rise to configuration and access to VPN
facilities.
[0078] Specifically, a user is presented with a login web page such
as that shown in FIG. 7 (or, in some embodiments, with an
alternative text or graphical login screen presentation).
Previously agreed on User ID and password information will be
authenticated after selection of the log in button at a client
presenting a web screen such as that in FIG. 7.
[0079] Successful login using the web page of FIG. 7 advantageously
causes the presentation of a main menu web page, illustratively of
the form of the web page shown in FIG. 8. In FIG. 8, a menu
including a list of available ISP (or other destination) selections
is presented at the left, with scrolling available when the list
exceeds the nominal list window size. Such menu entries will
include ISPs to which users at clients on LAN 301 subscribe. Upon
selection of a list entry, connection information associated with
the selection conveniently appears to the right of the list window,
in the area denominated NAME OF CONNECTION. Such connection
information need not be a network address, but will be an
appropriate logical specification of a connection sought to be
made. In some cases, a name of an ISP will be appropriate to
identify configuration information associated with the desired
connection. Selecting the CONNECT screen button then effects the
connection to the indicated ISP or other destination.
[0080] When a connection to a destination not specified in the menu
of the main menu web page of FIG. 8 is desired, provision is made
in the web page of FIG. 8 to select links to another web page
associated with connections in any of the illustrative categories
of connections shown in FIG. 8 below the NAME OF CONNECTION field
on that page. Specifically, Standard Dial-Up, Customized Dial-Up,
Fixed IP address Network, DHCP Network and PPPoE Network
connections are shown as available. In other contexts or
applications of the present inventive teachings, other particular
types of connections will, of course, be available for selection.
Selection of one of the illustrative connection-type links in FIG.
8 causes a follow-up web page to be sent to the selecting client
from GUI server 450 in FIG. 4. These and other web pages will be
discussed below in connection with FIGS. 9-16
[0081] Returning to FIG. 6, block 625 corresponds to selections
made at the main menu page of FIG. A or other pages to be discussed
below, as appropriate. The test at block 630 in FIG. 6 corresponds
to the selection by a user of the create a new connection link from
the main menu of FIG. A.
[0082] FIG. 9 is a web page provided by GUI server 450 when the
STANDARD DIAL-UP link is selected at the web page of FIG. 8 (for
the case that the desired connection is not listed in the menu at
the left in FIG. 8). In FIG. 9, provision is made for a user at a
client to enter a dial-up connection in the name of connection
field, and to enter appropriate user id and password inputs to be
used. Other information, such as phone number to dial, and options
to add special characters (such as 9 for an outside line, or (*70
to disable call waiting) are likewise entered as needed. Of course,
all information after the name of connection can be predicted in
many cases by storing prior sessions associated with the connection
name and retrieving appropriate parts of the prior session
information to complete the form of FIG. 9. In any event, provision
is made to edit presumed field information by selecting the edit
button when incomplete or erroneous information is presently
displayed. Editing screens will be described below.
[0083] Selection of the connect button in the screen of FIG. 9 will
cause a connection to be attempted based on the entered or accepted
information presented on that screen. Other choices that are
offered to a user at a client on LAN 301 by the network interface
unit 302, via its GUI server 450 include copying currently
displayed information for use in another connection (perhaps after
editing in the web page for such new connection) and deleting
currently displayed connection information. Further, most screens
presented by way of example in the present description include
status, disconnect, view syslog and close buttons to select the
respective well-known operations and displays.
[0084] FIG. 10 is a web page that is illustratively displayed upon
selecting the CUSTOMIZED DIAL-UP link from the main menu of FIG. 8
when the menu at the left of FIG. 8 fails to display a desired
connection. Thus, in FIG. 10, as in FIG. 9, a name of connection
field is completed and the remaining fields filled in (either
manually or by recognition of presumed information associated with
the name of connection information) before selecting connect.
Customized modem dial settings are employed when a more complex
digit or character string is needed to appropriately control a
dial-up modem session.
[0085] FIG. 11 is a web page that is illustratively displayed upon
selecting the FIXED-IP NETWORK link from the main menu of FIG. 8
when the menu at the left of FIG. 8 fails to display a desired
connection having a fixed IP address. As with the web pages of
FIGS. 9 and 10, a name of a network connection is filled in and the
other indicated information (ip_address, mask_address, and gateway)
retrieved from a prior session or filled in by at the client device
on LAN 301. Selecting the connect button again initiates the
connection to the indicated address.
[0086] FIG. 12 is a web page that is illustratively displayed upon
selecting the DHCP NETWORKS link from the main menu of FIG. 8 when
the menu at the left of FIG. 8 fails to display a desired
connection having a known temporary IP address. FIG. 12 shows a
screen that is presented by GUI server 450 upon selection of the
DHCP option at the main menu of FIG. 8. This screen allows the
insertion of a string used to identify DHCP client 415 in the
network interface unit of FIG. 4 to a network-based DHCP server
when a network connection (such as a connection on a cable network)
having a DHCP server to assign IP addresses. Thus, when a user
inserts a network ID associated with the network interface unit in
the Client: {Client Name} field and selects connect, the
network-based DHCP server returns a packet (often called an offer
packet) with at least one offered IP address. The network interface
unit DHCP client 415 then accepts an address from the offer packet
and notifies the network-based DHCP server of the selection so that
the IP connection is fully defined. The IP address thus accepted is
conveniently maintained at the network interface unit; this is a
wild side IP address by which the network interface unit will be
known on the Internet or other external network. In a complementary
manner, IP addresses are assigned to network interface unit 302
(illustratively from a pool of reserved address) by a network
administrator during a static setup of unit 302 will be used by
DHCP server 457 to identify clients on the client side of network
interface unit 302.
[0087] While not shown expressly in the attached drawing, PPPoE
connections are configured and setup in substantially the same
manner as dial-up connections (with login id and password, but
without a dialstring). Further, while not noted specifically for
the web pages of FIGS. 9-12, each of those web pages (as well as
others associated with connection-type-specifying links that will
be included on a web page such as that shown in FIG. 8) will
advantageously have a menu of connections from which the name of
the connection can be selected. That is, the menus of FIGS. 9-12
will in appropriate cases include available connections of the type
(standard dial-up, etc.) associated with the respective web pages,
rather than connections of all types as may be the case for the
menu of FIG. 8.
[0088] FIG. 13 is a web page displayed after a connection has been
established for selecting an identified service destination from
among those illustratively appearing in the menu at the left of the
web page. It proves convenient to display the URL of a selected
destination, as well as account and password information, which
will advantageously be stored in a memory such as 480 in FIG. 4 for
use on future attempts to access the particular service. When the
information is filled in the manner indicated, a connection to the
application is then sought by selecting the login button on the
screen of FIG. 13. Different particular connection profiles (for
particular fixed-IP, dial-up, etc.) will, of course, display
particular information fields appropriate to the service or
application. Thus, mail service will have one set of displayed
information fields, but other services (such as one of the
illustrative VCS services shown in FIG. 13) will employ other
particular fields.
[0089] When a desired link is not indicated in the list on the main
menu of FIG. 8, or is known not to be available as a selection in
one of the subordinate menus (such as the types shown in FIGS.
9-12) it proves advantageous to permit the specification of a new
connection by selecting the hypertext link create a new connection
in FIG. 8. In one illustrative context, selection of the create a
new connection link gives rise to the display of a new connection
form, illustratively having a layout shown in FIG. 14. User input
specified in block 635 in FIG. 6 is conveniently accomplished using
the form of FIG. 14. Specifically, in the form of FIG. 14, a name
is assigned to the desired connection, and the connection type is
selected, illustratively as one of two (or more) radio buttons such
as the dial-up connection and network connection radio buttons
shown in FIG. 14.
[0090] Additional information required in specifying a new
connection will, of course, depend on the nature of the connection.
The form of FIG. 14 provides for entry of information commonly
associated a selected connection type (dial-up or network). When a
dial-up connection has been selected at Step 2, login information
(User ID and password) for the dial-up connection is conveniently
specified, as is a further selection (by a respective one of the
radio buttons) between a standard dial-up connection or a dial-up
connection using a customized modem dialing string. When the latter
alternative is selected, the appropriate dialing string is also
entered in the indicated space. When a standard dial-up connection
is selected, then the (PSTN or other) phone number is entered,
along with additional optional information, such as an 8 or 9
typically used to select an outside line at a hotel or some office
spaces, and a code to disable call waiting, if applicable.
Selecting the Save button causes the entered configuration
information to be entered in associated portion of memory 475.
[0091] FIG. 15 is an example of an edit page presented by GUI
server 450 when an Edit button is selected in another (dial-up)
screen. In that page, the configuration information for an
identified dial-up connection is modified by entering additional or
alternative information, and the new configuration can be used to
replace an existing one or saved as a specified other connection.
FIG. 16 provides an editing form for network connections similar in
purpose to the edit form of FIG. 15 used for dial-up connections.
User inputs using the web page forms of FIGS. 15 and 16 correspond
to user input block 645 in FIG. 6 after a test for editing of a
pre-existing configuration.
[0092] Again returning to FIG. 6, following all editing of
configuration information using the operations at blocks 640 and
645, all available configuration information for a current link
from a requesting client is retrieved at block 650 and tested for
completeness at block 655 for the need for information derived by
DHCP server 457; if such a need exists, access to DHCP server (as
indicated by block 660) is effected. A similar test is made at
block 665 for needed DNS information and recourse is had to DNS
server 435 (block 670) as appropriate. Another test is
illustratively made for the completeness of key materials and other
IPsec information and, if any such configuration and operational
information needed for IP services, recourse is had to IPsec server
460, as indicated by block 680, labeled simply get key materials.
Other tests for completeness of configuration information will also
be performed when needed, as indicated by the test at 685 (with the
get other configuration information block 690) and the ellipsis
between blocks 675 and 685.
[0093] Finally, when configuration information has been found to be
complete, at block 685 the secure link (tunnel) is created and
communications proceeds over the link until a termination of the
session for any reason.
[0094] From the foregoing, it will be seen that illustrative
embodiments of the present invention provide flexible access to VPN
tunnels with reduced complexity relating to configuration of client
devices and secure network links. As will be appreciated,
substantially all of the required configuration information, as
well as operating system and interface unit software functions is
conveniently stored in network interface unit memory 475. Further,
this memory may assume the form of a flash card or other readily
removable memory device for additional network security.
[0095] The present invention has been described in the context of,
and provides operational advantages for one or more LANs, each
supporting a plurality of personal computers and other devices.
Thus, for example, a traveling business person will efficiently and
simply access a corporate headquarters LAN over the Internet by
connecting through a network interface unit supporting a variety of
client devices including one a laptop computer, web-enabled cell
phone, personal digital assistant and a variety of peripheral
devices. Such connections will be made from corporate branch
offices, customer offices, supplier offices, hotel rooms and, via
wireless links, from virtually anywhere. Such connections will be
available over dial-up, cable, DSL, private line, wireless and
other types of links, the configuration information for which will
be automatically derived using present inventive teachings.
[0096] While illustrative embodiments of the present invention have
been described in terms of a variety of servers, e.g., IPsec
server, DHCP server, and the like, it will be understood that such
servers represent functions advantageously performed in many cases
by a processor operating under the control of stored programs and
data in a network interface unit. In some embodiments it may prove
useful to have a dedicated processor to one or a group of such
servers or other functions, but in general controller 440 will be
realized using a general purpose processor, which processor will be
shared in carrying out the functions of the various servers,
clients and other elements of illustrative network interface unit
embodiments. It will prove convenient in many cases to have all
required programs, including an operating system, such as the
illustrative Linux operating system and the programs for performing
functions of the described elements on a single removable memory
unit, such as the above-mentioned flash memory card 485.
[0097] While the present invention has been described in terms of
illustrative network interface unit embodiments having a separate
physical identity from client devices, such as personal computers,
some embodiments will assume the form of an add-on device, such as
a peripheral card or pc card, or such network interface unit may be
built into a desktop, laptop, handheld or other computer, or may be
similarly built into a personal communicator, cell phone or
personal digital assistant. In appropriate cases, LAN hubs,
switches or network bridges can be combined and used with the
inventive network interface unit described herein to reduce the
proliferation of interconnecting devices that are required to
replicate in-office functionalities.
[0098] Configuration data for particular connections will
illustratively include two types: (1) files in a network interface
unit file system that are specific to each service application,
e.g., tunnel configuration information, is advantageously stored in
formats and file structures associated with security applications
running on the network interface device, such as the above-cited
Freeswan security software. DHCP server and DNS will illustratively
be of this type. Connection profiles, on the other hand, are
advantageously stored in a single flat file, illustratively of the
following type TABLE-US-00001 T tom@worldnet (fp) t dial i
987654321@worldnet.att.net w c*m!cb@@KSw3arword! n 5551212 p 9 . T
Anonymous DHCP t network . T @home DHCP t network c ZZ-123456X
.
[0099] In this illustrative arrangement, each profile begins with a
T line that contains the profile name. The end of the profile is a
line consisting of a single dot (period). Intermediate lines
include a tag and related information. These profile lines are
advantageously interpreted by scripts behind associated with GUI
server 450 as instructions describing how to create configuration
files of the first kind. For example, if @home DHCP is selected,
the script illustratively writes ZZ-123456X to DHCP client
configuration file as the client id, and launches the DHCP client
application 415.
[0100] The user environment is advantageously set up as a LAN thus
accommodating a large range of clients types, and a large range of
Internet connection types--all with a minimum amount of user
effort. At one end of the client device spectrum are printers,
typically having fairly limited configuration possibilities, and
which configurations are not easily changed after once being
configured. The other end of the device spectrum includes personal
computers and other flexible, programmable devices; these can be
configured in myriad different ways, but present a user with a high
level of configuration complexity. In each case connection to an
Ethernet LAN with easily realized configuration and operating
features in accordance with present inventive features proves
highly attractive.
[0101] On the (typically public) network side of the
above-described network interface unit (wild side), present
inventive teachings present a uniform mechanism for a user to
configure a wide variety of connection types, the details of which
are not apparent to the client machines. For example, a user may
have a preferred broadband service provider, but if broadband
service is temporarily unavailable, a dial-up connection can be
used in its place, and the client machines will see little effect
(other than reduced speed).
[0102] It proves advantageous in accordance with embodiments of the
present invention to store connection profile information in an
encrypted file system that is unlocked by successful authentication
of a user. So if a (highly portable network interface unit in
accordance with embodiments of the present is lost, stored
information is protected from unauthorized use.
* * * * *
References