System and method for providing network route redundancy across layer 2 devices
View Patent ↗Systems and methods are described for providing network route redundancy through Layer 2 devices, such as a loop free Layer 2 network having a plurality of switching devices. A virtual switch is coupled to the loop free Layer 2 network, the virtual switch having two or more switches configured to transition between master and backup modes to provide redundant support for the loop free Layer 2 network, the switches communicating their status through use of a plurality of redundancy control packets. The system also includes means for allowing the redundancy control packets to be flooded through the Layer 2 network. The means may include time-to-live data attached to the redundancy control packet which is decremented only when the packets are transferred through devices which are configured to recognize the protocol used in redundancy control packets.
1. A switch for use in a system of switches, the system of switches acting as a virtual switch, the switch comprising:
a memory; and
a plurality of ports, each for communicatively coupling the switch to a Layer 2 network,
wherein the switch is configured to act in concert with one or more other switches in the system of switches to provide route redundancy for the Layer 2 network, and
wherein the switch is configured to communicate its status to the one or more other switches by transmitting, via at least one of the plurality of ports, redundancy control packets for flooding throughout the Layer 2 network.
2. The switch of claim 1 , wherein each redundancy control packet includes a time-to-live data value, and wherein the time-to-live data value is decremented each time the redundancy control packet is transferred through a switch in the system of switches.
3. The switch of claim 1 , wherein the switch is configurable to operate in a master mode, a backup mode, and a master confirm mode.
4. The switch of claim 1 , wherein the switch, when operating in a first mode, is configured to forward all network traffic received at the switch and to transmit one or more redundancy control packets.
5. The switch of claim 4 , wherein the switch, when operating in a second mode, is configured to block all network traffic received at the switch except for redundancy control packets.
6. The switch of claim 5 , wherein the switch, when operating in a third mode, is configured to block all network traffic received at the switch except for redundancy control packets, and to transmit one or more redundancy control packets.
7. The switch of claim 3 , wherein each redundancy control packet includes a priority data value, and wherein the switch is configured to transition between backup mode, master confirm mode, and master mode based on priority data values included in redundancy control packets received at the switch and a stored priority data value for the switch.
8. The switch of claim 7 , wherein the switch, when operating in master mode or master confirm mode, is configured to transition to backup mode upon receipt of a redundancy control packet having a priority data value greater than the stored priority data value.
9. The switch of claim 7 , wherein the switch, when operating in backup mode, is configured to transition to master mode if no redundancy control packet including a priority data value greater than the stored priority data value is received within a predetermined amount of time.
10. The switch of claim 7 , wherein the switch, when operating in master confirm mode, is configured to transition to master mode once a predetermined number of redundancy control packets are transmitted by the switch.
11. The switch of claim 7 , wherein the stored priority data value is based on a number of live connections between the switch and devices in the Layer 2 network.
12. The switch of claim 11 , wherein the number of live connections is determined by broadcasting health check packets from the switch to the devices.
13. The switch of claim 11 , wherein the stored priority data value for the switch is further based on the quality of the live connections.
14. The switch of claim 1 , wherein the Layer 2 network is a loop free network.
15. The switch of claim 1 , wherein the switch is a Layer 2 switch.
16. The switch of claim 1 , wherein the switch is communicatively coupled with two or more VLANs in the Layer 2 network.
17. The switch of claim 16 , wherein the switch is configured to operate in a plurality of modes, and wherein the switch is capable of operating in a different mode with respect to each VLAN in the two or more VLANs.
18. A Layer 2 switch for use in a virtual switch, the Layer 2 switch comprising:
a memory component for storing a priority value for the Layer 2 switch; and
a control component configured to:
transition the Layer 2 switch from a first mode to a second mode upon receiving, from one or more other Layer 2 switches in the virtual switch, a redundancy control packet including a priority value less than the stored priority value;
transition the Layer 2 switch from the second mode to a third mode if no redundancy control packet including a priority data value greater than the stored priority data value is received from one or more other Layer 2 switches in the virtual switch within a predetermined amount of time; and
transition the Layer 2 switch from the second mode or the third mode to the first mode upon receiving, from one or more other Layer 2 switches in the virtual switch, a redundancy control packet including a priority value greater than the stored priority value.
19. A method performed in a switch usable in a virtual switch comprising a plurality of switches, the switch being configured to act in concert with one or more other switches in the plurality of switches to provide route redundancy for a Layer 2 network, the method comprising:
storing a priority value;
transitioning the switch to a first mode if a redundancy control packet is received by the switch having a priority value greater than the stored priority value;
transitioning the switch from the first mode to a second mode if a redundancy control packet having a priority value less than the stored priority value is received;
if in the second mode, transmitting a plurality of redundancy control packets; and
transitioning the switch from the second mode to a third mode if the number of transmitted redundancy control packets reaches a threshold.