Disaster recovery for active-standby data center using route health and BGP

• US 20060193247A1
• Filed: 02/25/2005
• Published: 08/31/2006
• Est. Priority Date: 02/25/2005
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Naseh, Zeeshan, Gundi, Vinay
• Granted Patent: US 7,710,865 B2
• Time in Patent Office: Days
• US Class Current: 370/216
• CPC Class Codes: H04L 45/04 Interdomain routing, e.g. hierarchical routing
• CPC Class Codes: H04L 45/22 Alternate routing
• CPC Class Codes: H04L 45/28 using route fault recovery

Abstract

The present invention provides an active/standby data center that avoids the delay associated with a cached DNS entry to switch from the active data center to the standby data center. When the active data center becomes unavailable, the standby data center advertises the same address as the primary data center so the change over occurs quickly. When the IP address of the primary data center is no longer visible to the standby data center, the standby data center begins to advertise.

Claims

1. A data center comprising:

An active data center coupled to at least two internet service providers;

A standby data center coupled to said active data center and to at least one of said internet service providers;

Means for switching from said active data center to said standby data center in the event of a disaster causing said active data center to be unavailable.

2. The data center of claim 1 wherein said switching means comprises:

means for advertising routes to said active data center to said internet service providers;

means for detecting the advertised routes by said standby data center;

means for broadcasting a conditional advertisement of the specific route to said standby data center.

3. The data center of claim 2 wherein said means for advertising comprises advertising a more specific route to the external BGP peer of the standby network if the prefix of the active data center is not in the BGP table of the standby data center.

4. The data center of claim 3 wherein said means for advertising further comprises monitoring an I-BGP link to receive an advertisement from said active data center and prohibiting the advertisement of said specific route to the external BGP peer of the standby network if the prefix of said active data center is received as a result of said monitoring.

5. In an active/standby data center, a method for making the standby data center available to network traffic in the event the active data center is not available, the method comprising the steps of:

redistributing IGP routes into BGP at both data centers;

conditionally advertising the prefix of interest from the primary data center into the I-BGP link; and

advertising the prefix of interest with a longer mask to the E-BGP peer of the secondary site router if the prefix of interest is not in the BGP table of the secondary data center router.

6. The method of claim 5 further comprising the step of receiving the prefix of interest from said active data center over an internal BGP link.

7. The method of claim 5 further comprising the step of receiving the prefix of interest from said active data center over a high bandwidth internal BGP link.

8. The method of claim 5 further comprising the step of using the advertise-map command to implement the BGP conditional advertisement.

9. A data center comprising:

An active data center coupled to at least two internet service providers;

A standby data center coupled to said active data center and to at least one of said internet service providers;

Means for injecting routes of interests into IGP using RHI such that the route to said standby data center is selected in the event of a disaster causing said active data center to be unavailable.

10. The data center of claim 10 wherein said active data center and standby data center are configured as an autonomous system coupled to at least two other autonomous systems and an edge router of said active data center is configured as:

router bgp 3 bgp log-neighbor-changes redistribute ospf 1 route-map OspfRouteFilter neighbor 141.41.248.130 remote-as 3 neighbor 142.41.248.130 remote-as 2 neighbor 151.41.248.129 remote-as 1 no auto-summary !

11. The data center of claim 10 wherein said router at said standby data center monitors a list of prefixes broadcast from said primary data center and, if the prefixes are missing, then said standby data center advertises a set of specified prefixes.

13. An autonomous system comprising:

an active data center, having a first IP address,

a first edge device coupling said active data center to the internet;

a standby data center having a second IP address identical to said first IP address;

a second edge device coupling said standby data center to the internet;

a communication link utilizing interior border gateway protocol to enable said first edge device to send route health updates to said second edge device; and

said second edge device adapted to conditionally route advertisement if said active data center is no longer active.

12. The data center of claim 14 wherein said router monitors a BGP routing table.

14. The autonomous system of claim 13 wherein said second edge device maintains a BGP table and compares a list of prefixes provided by the active data center to said BGP table.

15. The autonomous system of claim 14 wherein said second edge device further advertises a set of specified prefixes, and if the prefixes provided by said active data center are missing from the BGP table.

16. The autonomous system of claim 14 wherein said second edge device advertises a more specific route to the external BGP peer of the standby network if the prefix of the active data center is not in said BGP table.

17. The autonomous system of claim 16 wherein said second edge device is a network switch.

18. The autonomous system of claim 16 wherein said second edge device is a router.

19. The autonomous system of claim 14 wherein said second edge device is a network switch.

20. The autonomous system of claim 14 wherein said second edge device is a router.