Link Aggregation Control Protocol (LACP) Loop Detection
Link Aggregation Control Protocol (LACP) loop detection in a network that includes a Software Defined Networking (SDN) controller, a server and an edge switch is provided. The server virtualizes a virtual switch and virtual machines. The virtual switch includes uplink ports that are aggregated with downlink ports of the edge switch to form an aggregation group, and the SDN controller controls operation of the virtual switch. The virtual switch periodically sends a LACP data unit (LACPDU) message to the edge switch via each of the uplink ports in the aggregation group. The virtual switch receives a LACPDU message from the edge switch via one of the uplink ports in the aggregation group. When it is determined that the received LACPDU message originates from the virtual switch itself, the virtual switch keeping one of the uplink ports running and shutting down the rest of the uplink ports.
1 . A method of Link Aggregation Control Protocol (LACP) loop detection , the method being applicable in a network that includes a Software Defined Networking (SDN) controller, a server and an edge switch, wherein the server virtualizes a virtual switch and a plurality of virtual machines, the virtual switch includes a plurality of uplink ports that are aggregated with a plurality of downlink ports of the edge switch to form an aggregation group, and the SDN controller controls operation of the virtual switch, the method comprising:
the virtual switch periodically sending a LACP data unit (LACPDU) message to the edge switch via each of the plurality of uplink ports in the aggregation group;
the virtual switch receiving a LACPDU message from the edge switch via one of the plurality of uplink ports in the aggregation group; and
when it is determined that the received LACPDU message originates from the virtual switch itself, the virtual switch keeping one of the plurality of uplink ports running and shutting down the rest of the plurality of uplink ports.
2 . The method of claim 1 , wherein:
the LACPDU message sent to the edge switch includes a system identifier (ID) of the virtual switch, a source MAC address associated with the plurality of uplink ports in the aggregation group and an aggregation group ID of the aggregation group; and
the virtual switch determines that the received LACPDU message originates from the virtual switch itself based on the system ID, source MAC address and aggregation group ID.
3 . The method of claim 2 , wherein:
the LACPDU message sent to the edge switch includes a first value calculated based on the system ID, source MAC address and aggregation group ID; and
the virtual switch determines that the received LACPDU message originates from the virtual switch itself if the first value in the received LACPDU message is the same as a second value calculated based on the system ID, source MAC address and aggregation group ID.
4 . The method of claim 3 , wherein the first value and second value are calculated using message-digest algorithm MD5.
5 . The method of claim 3 , wherein the LACPDU message sent to the edge switch and the LACPDU message received from the edge switch are extended LACPDU messages, and the first value is carried in an extended Type Length Value (TLV) in the extended LACPDU messages.
6 . The method of claim 5 , wherein the method further comprises:
when it is determined that the received LACPDU message does not originate from the virtual switch, processing the received LACPDU message according to its content.
7 . The method of claim 1 , wherein the virtual switch is a Virtual Edge Port Aggregator (VEPA) switch, or the SDN controller is an OpenFlow controller, or both.
8 . A network device for Link Aggregation Control Protocol (LACP) loop detection, wherein the network device is capable of acting as a server,
wherein the server virtualizes a virtual switch and a plurality of virtual machines, the virtual switch includes a plurality of uplink ports that are aggregated with a plurality of downlink ports of an edge switch to form an aggregation group and a Software Defined Networking (SDN) controller controls operation of the virtual switch,
wherein the network device comprises interface to communicate with the SDN controller and edge switch, memory storing executable instructions, and a processor to execute instructions to implement the virtual switch to:
send a LACP data unit (LACPDU) message to the edge switch via each of the plurality of uplink ports in the aggregation group periodically;
receive a LACPDU message from the edge switch via one of the plurality of uplink ports in the aggregation group; and
when it is determined that the received LACPDU message is the LACPDU sent by the virtual switch itself, keep one of the plurality of uplink ports running and shut down the rest of the plurality of uplink ports.
9 . The network device of claim 8 , wherein:
the LACPDU message sent to the edge switch includes a system identifier (ID) of the virtual switch, a source MAC address associated with the plurality of uplink ports in the aggregation group and an aggregation group ID of the aggregation group; and
the virtual switch is to determine that the received LACPDU message originates from the virtual switch itself based on the system ID, source MAC address and aggregation group ID.
10 . The network device of claim 9 , wherein:
the LACPDU message sent to the edge switch includes a first value calculated based on the system ID, source MAC address and aggregation group ID; and
the virtual switch is to determine that the received LACPDU message originates from the virtual switch itself if the first value in the received LACPDU message is the same as a second value calculated based on the system ID, source MAC address and aggregation group ID.
11 . The network device of claim 10 , wherein the first value and second value are calculated using message-digest algorithm MD5.
12 . The network device of claim 10 , wherein the LACPDU message sent to the edge switch and the LACPDU message received from the edge switch are extended LACPDU messages, and the first value is carried in an extended Type Length Value (TLV) in the extended LACPDU messages.
13 . The network device of claim 12 , wherein the method further comprises:
when it is determined that the received LACPDU message does not originate from the virtual switch, the virtual switch is to process the received LACPDU message according to its content.
14 . The network device of claim 8 , wherein the virtual switch is a Virtual Edge Port Aggregator (VEPA) switch or the SDN controller is an OpenFlow controller, or both.
15 . A non-transitory computer readable medium encoded with executable instructions for execution by a processor of a server that implements a virtual switch, wherein the virtual switch is managed by a Software Defined Networking (SDN) controller and the processor is to execute the instructions to:
periodically send a LACP data unit (LACPDU) message to an edge switch via uplink ports aggregated with downlink ports of the edge switch in an aggregation group;
receive a LACPDU message from the edge switch via one of the uplink ports in the aggregation group; and
when it is determined that the received LACPDU message is the LACPDU sent by the virtual switch itself, keep one of the uplink ports running and shut down the rest of the uplink ports.