Trunk / VPC Port-Channel not working properly with Nexus 9K / 2K (FEX) : Spanning-tree involved
Hello DevCentral, I'll present to you an odd behavior using 2 Nexus 9k (9.2.1) with Nexus 2k as Fex on which two Big-IP i4600 (12.1.4) are connected. Our Setup : The two Big-IP are configured in a device-group, Each Big-IP is connected to two Nexus 2k (FEX) in the same aggregate using VPV technology on the Nexus. The configuration match this KB : https://support.f5.com/csp/article/K13142 Spanning-tree is disabled on interfaces and Trunk on the Big-IP Flow Control is disabled on the Big-IP and the Nexus The Big-IP are connected to multiples VLANS using "Tagged Interfaces" option (802.1q tag on packets) Observations with this spanning-tree setup on the VPC configured on the Nexus : spanning-tree port type edge spanning-tree bpduguard enable Observation 1: When every interface is up, everything work properly Observation 2: If I shut one or the other interface of Port-channel1 on the switch everything is ok, If I shut both interfaces of Port-channel1 the aggregate is seen "Down", If I "no shut" interface1 of Port-channel1 the aggregate is rebuild and works after few seconds. Observation 3: If I shut one or the other interface of Port-channel1 on the switch everything is ok, If I shut both interfaces of Port-channel1 the aggregate is seen "Down", If I "no shut" interface2 of Port-channel1 the aggregate is rebuild but packets are not forwarded to/from this interface. Observations with this spanning-tree setup on the VPC configured on Nexus (notice the word trunk added): spanning-tree port type edge trunk spanning-tree bpduguard enable Observation 1: When every interface is up, everything work properly Observation 2: If I shut one or the other interface of Port-channel1 on the switch everything is ok, If I shut both interfaces of Port-channel1 the aggregate is seen "Down", If I "no shut" interface1 of Port-channel1 the aggregate is rebuild and works after few seconds. Observation 3: If I shut one or the other interface of Port-channel1 on the switch everything is ok, If I shut both interfaces of Port-channel1 the aggregate is seen "Down", If I "no shut" interface2 of Port-channel1 the aggregate is rebuild and works after few seconds. General Observations: There is no error detected on the interfaces/Port-Channel on the Nexus There is no error detected on the interfaces/Port-Channel on the Big-IP Conclusion: "spanning-tree port type edge", is not working for this setup "spanning-tree port type edge trunk", is working for this setup Question: Can someone explain what's happening here ? Regards my fellow companions.