Firewall providing enhanced network security and user transparency

• US 7,249,376 B2
• Filed: 11/07/2003
• Issued: 07/24/2007
• Est. Priority Date: 02/06/1996
• Status: Expired due to Fees

• Current Assignee: GraphOn Nes Sub, LLC (Hopto Inc.)
• Original Assignee: GraphOn Nes Sub, LLC (Hopto Inc.)
• Inventors: Wesinger, Jr., Ralph E., Coley, Christopher D.
• Primary Examiner(s): Zia, Syed A.
• Application Number:
  US10/703,821
• Publication Number:
  US 20050149747A1
• Time in Patent Office: 1,355 Days
• Field of Search: None
• US Class Current: 726/11
• CPC Class Codes: B65B 11/004 in blanks, e.g. sheets precut and creased for folding
• CPC Class Codes: G06F 16/958 Organisation or management of web site content, e.g. publishing, maintaining pages or automatic linking
• CPC Class Codes: G06F 21/42 using separate channels for security data
• CPC Class Codes: G06Q 20/027 involving a payment switch or gateway
• CPC Class Codes: H04L 2101/677 Multiple interfaces, e.g. multihomed nodes
• CPC Class Codes: H04L 61/25 of the same type
• CPC Class Codes: H04L 61/2514 between local and global IP addresses
• CPC Class Codes: H04L 61/2521 Translation architectures other than single NAT servers
• CPC Class Codes: H04L 61/256 NAT traversal
• CPC Class Codes: H04L 61/35 involving non-standard use of addresses for implementing network functionalities, e.g. coding subscription information within the address or functional addressing, i.e. assigning an address to a function
• CPC Class Codes: H04L 61/4511 using domain name system [DNS]
• CPC Class Codes: H04L 61/4552 Lookup mechanisms between a plurality of directories; Synchronisation of directories, e.g. metadirectories
• CPC Class Codes: H04L 63/02 for separating internal from external traffic, e.g. firewalls
• CPC Class Codes: H04L 63/0227 Filtering policies mail message filtering H04L51/212
• CPC Class Codes: H04L 63/0263 Rule management
• CPC Class Codes: H04L 63/0281 Proxies
• CPC Class Codes: H04L 63/0807 using tickets, e.g. Kerberos cryptographic mechanisms or cryptographic arrangements for entity authentication using tickets or tokens H04L9/3213
• CPC Class Codes: H04L 63/18 using different networks or channels, e.g. using out of band channels cryptographic mechanisms or cryptographic arrangements for key distribution involving distinctive intermediate devices or communication paths H04L9/0827; cryptographic mechanisms or cryptographic arrangements for authentication using a plurality of channels H04L9/3215
• CPC Class Codes: H04L 69/16 Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP]
• CPC Class Codes: H04L 69/164 Adaptation or special uses of UDP protocol
• CPC Class Codes: H04L 9/40 : Network security protocols

Abstract

The present invention provides a firewall that achieves maximum network security and maximum user convenience. The firewall employs “envoys” that exhibit the security robustness of prior-art proxies and the transparency and ease-of-use of prior-art packet filters, combining the best of both worlds. No traffic can pass through the firewall unless the firewall has established an envoy for that traffic. Both connection-oriented (e.g., TCP) and connectionless (e.g., UDP-based) services may be handled using envoys. Establishment of an envoy may be subjected to a myriad of tests to “qualify” the user, the requested communication, or both. Therefore, a high level of security may be achieved. The usual added burden of prior-art proxy systems is avoided in such a way as to achieve fall transparency-the user can use standard applications and need not even know of the existence of the firewall. To achieve full transparency, the firewall is configured as two or more sets of virtual hosts. The firewall is, therefore, “multi-homed,” each home being independently configurable. One set of hosts responds to addresses on a first network interface of the firewall. Another set of hosts responds to addresses on a second network interface of the firewall. In one aspect, programmable transparency is achieved by establishing DNS mappings between remote hosts to be accessed through one of the network interfaces and respective virtual hosts on that interface. In another aspect, automatic transparency may be achieved using code for dynamically mapping remote hosts to virtual hosts in accordance with a technique referred to herein as dynamic DNS, or DDNS.

Claims

1. A multi-homed firewall including dynamically updating domain name server mappings:

a firewall device for interfacing a first private network and a public network;

a plurality of virtual hosts associated with the firewall device, each of said virtual hosts corresponding to a home through which a connection may be made through the firewall device;

a domain name server (DNS) for providing DNS mappings between the plurality of virtual hosts and said firewall device; and

wherein said DNS mappings are dynamically updated.

2. The multi-homed firewall of claim 1, wherein said firewall device is realized using a plurality of physical firewall devices electrically coupled in parallel, each physical firewall device further including a plurality of associated virtual hosts, and wherein DNS mapping between the plurality of physical machines and corresponding virtual hosts are dynamically updated.

3. The multi-homed firewall of claim 2, wherein said DNS mappings are dynamically performed with the load of said plurality of physical firewall machines taken into account.

4. The multi-homed firewall of claim 3, wherein the functions of a first firewall machine are performed by the virtual hosts of a different physical firewall machine if said first firewall machine fails.

5. The multi-homed firewall of claim 1, wherein said firewall device further comprises a configurator for providing a web-based front-end for configuring said firewall through a point-and-click interface using a web browser.

6. A multi-homed firewall including dynamically updating domain name server mappings:

firewall means for interfacing a first private network and a public network;

a plurality of virtual host means associated with the firewall means for allowing a connection to be made through said firewall means;

means for providing DNS mappings between the plurality of virtual host means and said firewall means; and

means for dynamically updating the DNS mappings.

7. The multi-homed firewall of claim 6, wherein said firewall means is realized using a plurality of physical firewall devices electrically coupled in parallel, each physical firewall device further including a plurality of associated virtual host means, and wherein DNS mapping between the plurality of physical devices and corresponding virtual host means are dynamically updated.

8. The multi-homed firewall of claim 7, wherein said DNS mappings are dynamically performed with the load of said plurality of physical firewall machines taken into account.

9. The multi-homed firewall of claim 8, wherein the functions of a first firewall machine are performed by the virtual hosts of a different physical firewall machine if said first firewall machine fails.

10. The multi-homed firewall of claim 6, wherein said firewall device further comprises configurator means for providing a web-based front-end for configuring said firewall through a point-and-click interface using a web browser.

11. A multi-homed firewall including dynamically updating domain name server mappings:

a plurality of virtual hosts associated with a firewall device, each of said virtual hosts corresponding to a home through which a connection may be made through the firewall device between a private and public network; and

a domain name server (DNS) for providing dynamically updating DNS mappings between the plurality of virtual hosts and said firewall device.

12. The multi-homed firewall of claim 11, wherein said firewall device is realized using a plurality of physical firewall devices electrically coupled in parallel, each physical firewall device further including a plurality of associated virtual hosts, and wherein DNS mapping between the plurality of physical machines and corresponding virtual hosts are dynamically updated.

13. The multi-homed firewall of claim 12, wherein said DNS mappings are dynamically performed with the load of said plurality of physical firewall machines taken into account.

14. The multi-homed firewall of claim 13, wherein the functions of a first firewall machine are performed by the virtual hosts of a different physical firewall machine if said first firewall machine fails.

15. The multi-homed firewall of claim 11, wherein said firewall device further comprises a configurator for providing a web-based front-end for configuring said firewall through a point-and-click interface using a web browser.