Fault tolerant firewall sandwiches

• US 20030131262A1
• Filed: 10/18/2002
• Published: 07/10/2003
• Est. Priority Date: 10/18/2001
• Status: Active Grant

• Current Assignee: Board of Regents of the University of Nebraska
• Original Assignee: Board of Regents of the University of Nebraska
• Inventors: Goddard, Stephen M.
• Granted Patent: US 7,254,834 B2
• Time in Patent Office: Days
• US Class Current: 713/201
• CPC Class Codes: H04L 63/0218 Distributed architectures, e.g. distributed firewalls
• CPC Class Codes: H04L 67/1001 for accessing one among a plurality of replicated servers
• CPC Class Codes: H04L 67/1006 with static server selection, e.g. the same server being selected for a specific client
• CPC Class Codes: H04L 67/1008 based on parameters of servers, e.g. available memory or workload monitoring of computer activity G06F11/30
• CPC Class Codes: H04L 67/1017 based on a round robin mechanism
• CPC Class Codes: H04L 67/1034 Reaction to server failures by a load balancer
• CPC Class Codes: H04L 67/60 Scheduling or organising the servicing of application requests, e.g. requests for application data transmissions using the analysis and optimisation of the required network resources admission control or resource allocation H04L47/70
• CPC Class Codes: H04L 69/40 for recovering from a failure of a protocol instance or entity, e.g. service redundancy protocols, protocol state redundancy or protocol service redirection management of faults, events, alarms or notifications in data switching networks H04L41/06

Abstract

Firewall sandwich configurations having improved levels of system availability as well as an application-space implementation of a firewall load balancer (FLB) which provides greater operational flexibility while reducing the need for custom hardware and/or operating system software. Also disclosed is a firewall capable of functionally replacing an FLB upon detecting a failure therein.

Claims

1. A computer-readable medium comprising computer-executable instructions for performing a method in application-space, said method comprising:

receiving a packet from a computer network;

selecting one of a plurality of firewalls for processing the packet; and

forwarding the packet to the selected one of the firewalls.

2. The computer-readable medium of claim 1 further comprising:

determining whether the packet is associated with an existing connection; and

wherein selecting includes selecting one of the firewalls as a function of the determining step.

3. The computer-readable medium of claim 1 wherein said computer-executable instructions enable performance of said method on COTS hardware.

4. The computer-readable medium of claim 1 wherein said computer-executable instructions enable performance of said method on COTS hardware executing COTS OS software.

5. The computer-readable medium of claim 1 further comprising:

determining whether a failure has occurred in an associated FLB; and

if the failure has occurred, functionally replacing the associated FLB.

6. The computer-readable medium of claim 1 further comprising:

determining whether a failure has occurred in either one of a first associated FLB and a second associated FLB; and

if the failure has occurred, functionally replacing the first associated FLB or the second associated FLB in which the failure occurred.

7. The computer-readable medium of claim 1 wherein the instructions enable operation in either one of a single-FLB mode and a dual-FLB mode.

8. The computer-readable medium of claim 1 wherein the instructions include instructions for operating as a firewall, and instructions for converting operation to a FLB upon determining that a failure has occurred in an associated FLB.

9. A system comprising:

a plurality of firewalls;

a first FLB for exchanging packets between a first network and the plurality of firewalls;

a second FLB for exchanging packets between a second network and the plurality of firewalls; and

a first standby FLB configured to detect a failure in either one of the first FLB and the second FLB, and to functionally replace a corresponding one of the first FLB and the second FLB after detecting the failure.

10. The system of claim 9 wherein the first FLB and the second FLB are application-space FLBs.

11. The system of claim 10 wherein the application-space FLBs are embodied in COTS hardware executing COTS OS software.

12. The system of claim 9 further comprising a second standby FLB configured to functionally replace the first standby FLB upon detecting that the first standby FLB no longer serves a standby function for the first FLB and the second FLB.

13. A system comprising:

a plurality of firewalls;

a first FLB for exchanging packets between a first network and the plurality of firewalls; and

a second FLB for exchanging packets between a second network and the plurality of firewalls;

wherein at least the first FLB is configured to both exchange packets between the first network and the plurality of firewalls, and exchange packets between the second network and the plurality of firewalls, after determining that a failure has occurred in the second FLB.

14. The system of claim 13 wherein the second FLB is configured to both exchange packets between the first network and the plurality of firewalls, and exchange packets between the second network and the plurality of firewalls, after determining that a failure has occurred in the first FLB.

15. The system of claim 13 wherein the first FLB and the second FLB are application-space FLBs.

16. The system of claim 13 further comprising at least one standby FLB configured to functionally replace the second FLB upon determining that the failure has occurred in the second FLB.

17. The system of claim 16 wherein the first FLB is configured to both exchange packets between the first network and the plurality of firewalls, and exchange packets between the second network and the plurality of firewalls, after determining that the failure has occurred in the second FLB and a failure has occurred in the standby FLB.

18. The system of claim 13 further comprising at least one standby FLB configured to functionally replace the first FLB upon determining that a failure has occurred in the first FLB.

19. The system of claim 13 further comprising at least one standby FLB configured to determine whether a failure has occurred in either one of the first FLB and the second FLB, and to functionally replace the corresponding one of the first FLB and the second FLB upon determining that the failure has occurred.

20. A system comprising:

a plurality of firewalls;

a first FLB for exchanging packets between a first network and the plurality of firewalls; and

a second FLB for exchanging packets between a second network and the plurality of firewalls;

wherein at least one of the firewalls is configured to functionally replace the first FLB after detecting a failure in the first FLB.

21. The system of claim 20 wherein each of the firewalls is configured to functionally replace the first FLB after detecting a failure in the first FLB.

22. The system of claim 21 wherein each of the firewalls is configured to functionally replace either one of the first FLB and the second FLB after detecting a failure in a corresponding one of the first FLB and the second FLB.

23. The system of claim 20 wherein said one of the firewalls is configured to functionally replace either one of the first FLB and the second FLB after detecting a failure in a corresponding one of the first FLB and the second FLB.