Synchronizing multicast information for linecards

• US 9,094,221 B2
• Filed: 06/24/2013
• Issued: 07/28/2015
• Est. Priority Date: 03/19/2010
• Status: Expired due to Fees

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Brocade Communications Systems, Inc. (Broadcom, Inc.)
• Inventors: Dholakia, Mehul, Yeung, Wing-Keung Adam, Pudiyapura, Ajeer S.
• Primary Examiner(s): HSU, ALPUS
• Application Number:
  US13/925,723
• Publication Number:
  US 20140029613A1
• Time in Patent Office: 764 Days
• US Class Current: 1/1
• CPC Class Codes: H04L 12/18 for broadcast or conference , e.g. multicast
• CPC Class Codes: H04L 12/4641 Virtual LANs, VLANs, e.g. virtual private networks [VPN] LAN interconnection over a bridge based backbone H04L12/462; encapsulation techniques H04L12/4633; routing of packets H04L45/00; packet switches H04L49/00; virtual private networks for security H04L63/0272
• CPC Class Codes: H04L 45/16 Multipoint routing
• CPC Class Codes: H04L 45/586 of virtual routers
• CPC Class Codes: H04L 49/201 Multicast operation; Broadcast operation
• CPC Class Codes: H04L 49/354 for supporting virtual local area networks [VLAN]

Abstract

In a network device comprising redundant management processors and one or more linecard processors situated on one or more linecards, a linecard processor maintains multicast information that is synchronized with multicast information, or a portion thereof, maintained by an active management processor. When a switchover is performed due to which a previous standby management processor becomes the new active management processor, the switchover is performed without interrupting any multicast routing services provided by the network device. For example, a switchover may be performed in order to upgrade a linecard processor to a new software version.

Claims

1. A system comprising:

a set of ports;

a first processor configurable to perform a set of multicast routing-related functions and to maintain a first routing information usable for performing the set of multicast routing-related functions; and

a packet processor with associated one or more memories and a linecard processor coupled to a volatile memory;

wherein the linecard processor is configurable to;

maintain a second routing information in the volatile memory based on the first routing information;

program, based on the second routing information, a first memory from the associated one or more memories with a third routing information, the third routing information used by the packet processor to facilitate forwarding of a multicast packet;

enable correlation information to be preserved across a reboot of the linecard processor; and

upon reboot of the linecard processor;

build a fourth routing information in the volatile memory; and

link the fourth routing information with the third routing information used by the packet processor, using the correlation information.

2. The system of claim 1, wherein the correlation information links an entry in the fourth routing information stored in the volatile memory to an entry in the associated one or more memories with the packet processor.

3. The system of claim 1, wherein the packet processor is configurable to:

extract routing information from the multicast packet; and

determine, based upon the extracted routing information and the third routing information, multiple ports to be used for forwarding the multicast packet.

4. The system of claim 1, wherein the packet processor is configurable to:

extract routing information from the multicast packet; and

determine, based upon the extracted routing information and the third routing information, multiple virtual LANs (VLANs) associated with a port to which the multicast packet is to be forwarded.

5. The system of claim 1, wherein the first routing information, the second routing information and the fourth routing information comprise multicast routes-related information and rendezvous point-related information.

6. The system of claim 1, wherein the system further comprises a linecard that is coupled to at least one port from the set of ports and the linecard comprises the linecard processor and the packet processor.

7. A network device comprising:

a set of ports;

a first processor configurable to perform a set of multicast routing-related functions and to maintain a first routing information usable for performing the set of multicast routing-related functions;

a third processor with associated one or more memories, wherein the third processor is configurable to use a third routing information to facilitate forwarding of a multicast packet; and

a second processor, the second processor configurable to;

maintain a second routing information in a volatile memory based on the first routing information;

program, based on the second routing information, a first memory from the associated on one or more memories with the third routing information;

enable correlation information to be preserved across a reboot of the second processor; and

upon reboot of the second processor;

build a fourth routing information in the volatile memory; and

link the fourth routing information with the third routing information used by the third processor, using the correlation information.

8. The network device of claim 7, wherein the correlation information links an entry in the fourth routing information stored in the volatile memory to an entry in the associated one or more memories with the third processor.

9. The network device of claim 7, wherein the third processor is configurable to:

extract routing information from the multicast packet; and

determine, based upon the extracted routing information and the third routing information, multiple ports to be used for forwarding the multicast packet.

10. The network device of claim 7, wherein the third processor is configurable to:

extract routing information from the multicast packet; and

determine, based upon the extracted routing information and the third routing information, multiple virtual LANs (VLANs) associated with a port to which the multicast packet is to be forwarded.

11. The network device of claim 7, wherein the first routing information, the second routing information and the fourth routing information comprise multicast routes-related information and rendezvous point-related information.

12. The network device of claim 7, wherein the network device further comprises a linecard that is coupled to at least one port from the set of ports and the linecard comprises the linecard processor and the packet processor.