High availability bridging between layer 2 networks
The technology disclosed herein enables high availability bridging between Layer 2 (L2) networks. In a particular embodiment, a method includes high availability bridge cluster comprising a first bridge node and a second bridge node. The first and second bridge nodes include first and second active bridges and first and second standby bridges, respectively. The method provides, in the first active bridge, bridging network communications between two or more L2 networks. The second standby bridge acts as a failover bridge for the first active bridge. The method further provides generating a failure detection message that incorporates a hardware address of the first bridge node and transferring the failure detection message from the first bridge node to the second bridge node. In the second standby bridge, the method provides receiving the failure detection message and using the hardware address to synchronize bridging information between the first active bridge and the second standby bridge.
1. A method of operating a high availability bridge cluster comprising a first network bridge node and a second network bridge node for high availability Layer 2 (L2) network bridging, wherein the first network bridge node includes a first active bridge and a first standby bridge and the second network bridge node includes a second active bridge and a second standby bridge, the method comprising:
in the first active bridge, bridging first network communications between two or more L2 networks, wherein the second standby bridge acts as a failover bridge for the first active bridge;
in the first active bridge, generating a failure detection message that incorporates a hardware address of the first network bridge node;
transferring the failure detection message from the first network bridge node to the second network bridge node;
in the second standby bridge, receiving the failure detection message and using the hardware address to synchronize bridging information between the first active bridge and the second standby bridge.
2. The method of claim 1 , further comprising:
in the second active bridge, bridging second network communications between the two or more L2 networks, wherein the first standby bridge acts as a failover bridge for the second active bridge;
generating a second failure detection message that incorporates a second hardware address of the second network bridge node;
transferring the second failure detection message from the second network bridge node to the first network bridge node;
in the first standby bridge, receiving the second failure detection message and using the second hardware address to synchronize second bridging information between the second active bridge and the first standby bridge.
3. The method of claim 1 , wherein using the hardware address to synchronize the bridging information comprises:
identifying a first management plane network address for the first network bridge node associated with the hardware address;
using the first management plane network address to provide the first network bridge node with a second management plane network address for the second network bridge node; and
exchanging the bridging information between the first and second network bridge nodes using the first and second management plane network addresses.
4. The method of claim 1 , wherein the bridging information includes hardware addresses of elements in the first network communications that are learned by the first active bridge while bridging the first network communications.
5. The method of claim 4 , further comprising:
upon activation of the second standby bridge, using the reverse address resolution protocol (RARP) with the hardware addresses to notify physical L2 network switches to direct the first network communications having the hardware addresses to the second standby bridge.
6. The method of claim 1 , further comprising:
activating the second standby bridge upon not receiving at least one subsequent failure detection message from the first network bridge node.
7. The method of claim 1 , wherein the failure detection message comprises one or more packets in a bidirectional forwarding detection (BFD) session between the first and second network bridge nodes.
8. The method of claim 7 , wherein the BFD session operates over a link layer protocol within Internet Protocol (IP).
9. The method of claim 8 , wherein the link layer protocol comprises Ethernet.
10. The method of claim 1 , wherein the high availability bridge cluster is assigned a uniform unique identifier (UUID).
11. A system for implementing a high availability bridge cluster for high availability Layer 2 (L2 ) network bridging, the system comprising:
a first network bridge node including a first active bridge and a first standby bridge; and
a second network bridge node including a second active bridge and a second standby bridge;
wherein the first active bridge bridges first network communications between two or more L2 networks, wherein the second standby bridge acts as a failover bridge for the first active bridge, generates a failure detection message that incorporates a hardware address of the first network bridge node, and transfers the failure detection message from the first network bridge node to the second network bridge node;
wherein the second standby bridge receives the failure detection message and uses the hardware address to synchronize bridging information between the first active bridge and the second standby bridge.
12. The system of claim 11 , wherein:
the second active bridge bridges second network communications between the two or more L2 networks, wherein the first standby bridge acts as a failover bridge for the second active bridge, generates a second failure detection message that incorporates a second hardware address of the second network bridge node, and transfers the second failure detection message from the second network bridge node to the first network bridge node;
the first standby bridge receives the second failure detection message and using the second hardware address to synchronize second bridging information between the second active bridge and the first standby bridge.
13. The system of claim 11 , wherein to use the hardware address to synchronize the bridging information, the second standby bridge:
identifies a first management plane network address for the first network bridge node associated with the hardware address;
uses the first management plane network address to provide the first network bridge node with a second management plane network address for the second network bridge node; and
exchanges the bridging information between the first and second network bridge nodes using the first and second management plane network addresses.
14. The system of claim 11 , wherein the bridging information includes hardware addresses of elements in the first network communications that are learned by the first active bridge while bridging the first network communications.
15. The system of claim 14 , wherein the second standby bridge, upon activation, uses the reverse address resolution protocol (RARP) with the hardware addresses to notify physical L2 network switches to direct the first network communications having the hardware addresses to the second standby bridge.
16. The system of claim 11 , wherein the second standby bridge activates upon not receiving at least one subsequent failure detection message from the first network bridge node.
17. The system of claim 11 , wherein the failure detection message comprises one or more packets in a bidirectional forwarding detection (BFD) session between the first and second network bridge nodes.
18. The system of claim 17 , wherein the BFD session operates over a link layer protocol within Internet Protocol (IP).
19. The system of claim 17 , wherein the link layer protocol comprises Ethernet.
20. The system of claim 11 , wherein a high availability bridge cluster is assigned a uniform unique identifier (UUID).