Advertising Reachability In Proxy FHRP for Anycast Routing Service

• US 20140126376A1
• Filed: 01/14/2014
• Published: 05/08/2014
• Est. Priority Date: 08/15/2011
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Rai, Smita, Mishra, Chandan, Ramachandran, Gayatri, Sane, Sanjay
• Granted Patent: US 9,584,421 B2
• Time in Patent Office: Days
• US Class Current: 370/235
• CPC Class Codes: H04L 45/125 based on throughput or bandwidth
• CPC Class Codes: H04L 45/58 Association of routers
• CPC Class Codes: H04L 45/66 Layer 2 routing, e.g. in Ethernet based MAN's
• CPC Class Codes: H04L 47/125 by balancing the load, e.g. traffic engineering

Abstract

Embodiments described herein achieve proxy FHRP for anycast routing services through the coordination of L2MP edge switches to allow load balancing for the use of routing services. Such embodiments may avoid duplicity and coordinate control planes between the edge switches to present a proxy interface to the rest of the network for the routing services. As such, multipathing and load-balancing for efficient use of crucial services may be provided for client nodes inside the network.

Claims

1. A method comprising:

A method comprising;

receiving one or more HSRP packets;

terminating the HSRP packets;

consuming the HSRP packets;

electing a primary HSRP proxy from the plurality of cloud network junction devices;

exchanging received HSRP information with one or more other network devices;

periodically deciding whether to advertise reachability to an emulated switch;

discontinuing the advertisement after detecting a mismatch, and

directing traffic from a first network device through the primary HSRP proxy to the emulated switch.

2. The method of claim 1, wherein the cloud network junction devices are edge switches between an DCE cloud and an L3 network.

3. The method of claim 2, further comprising:

routing the traffic through one or more ECMP devices between the first network device and the emulated switch.

4. The method of claim 2, further comprising:

operating one or more routers in the L3 network as HSRP active.

5. The method of claim 2, wherein the step of filtering further comprises:

intercepting HSRP control packets to prevent forwarding of the packets to the DCE cloud; and

punting the HSRP control packets to a supervisor device.

6. The method of claim 5, further comprising:

programming a MAC table with the HSRP virtual MAC pointing to the router-facing interfaces.

7. The method of claim 5, further comprising:

searching for active routers;

after finding no active routers, declaring the network device performing the searching as active and ready to forward L3 traffic.

8. A method comprising:

receiving one or more HSRP packets;

terminating the HSRP packets;

consuming the HSRP packets;

exchanging received HSRP information with one or more other network devices;

periodically deciding whether to advertise reachability to an emulated switch; and

after detecting a mismatch, discontinuing the advertisement.

9. The method of claim 8, wherein the HSRP information is condensed information containing at least a virtual IP address and a virtual MAC address.

10. The method of claim 8, further comprising:

electing one of the network devices to respond to ARP messages to one or more hosts in a DCE cloud.

11. The method of claim 10, further comprising:

obtaining HSRP virtual MAC information from terminated HSRP packets.

12. The method of claim 11, further comprising:

electing a second network device to respond to ARP messages after it is determined that the second network device is connected to a router with higher priority.

13. The method of claim 12, further comprising:

trapping the received ARP messages; and

punting the received ARP messages.

14. A network device comprising:

a processor programmed to;

receive a unicast packet flood;

determine an outer designated address;

reference a MAC match table with an inner designated address to direct packets;

program an ACL to drop received packets with the inner designated address and an outer designated address; and

respond with identification information for an emulated switch.

15. The network device of claim 14 wherein the inner designated address is a HSRP virtual MAC address.

16. The network device of claim 14, wherein the network device is one of a network switch or a network router.

17. The network device of claim 15, wherein the processor is further programmed to:

trap a unicast ARP based on gateway IP information and target IP address information.

18. The network device of claim 15, wherein the network device is located on a co-located DCE/L3 boundary.

19. The network device of claim 17, wherein the processor is further programmed to:

forward the unicast traffic to the emulated switch.

20. The network device of claim 15, wherein the network device is in communication with a switched virtual interface.