When downgrading the Nexus 5672 back to NX-OS 7.0(2)N1(1) the connection is fine again, interface eth 1/1 on the Nexus switch is not blocked anymore and chooses the correct root bridge (which is the 3750): Operational Trunking Encapsulation: dot1qĪdministrative Native VLAN tagging: enabledĪdministrative private-vlan host-association: noneĪdministrative private-vlan mapping: noneĪdministrative private-vlan trunk Native VLAN tagging: enabledĪdministrative private-vlan trunk associations: noneĪdministrative private-vlan trunk mappings: none Sw-3750-01# show interfaces gigabitEthernet 3/0/1 switchportĪdministrative Trunking Encapsulation: dot1q Sw-5672-01# show interface ethernet 1/1 switchportĮxtended Trust State : not trusted Īdministrative private-vlan primary host-association: noneĪdministrative private-vlan secondary host-association: noneĪdministrative private-vlan primary mapping: noneĪdministrative private-vlan secondary mapping: noneĪdministrative private-vlan trunk native VLAN: noneĪdministrative private-vlan trunk encapsulation: dot1qĪdministrative private-vlan trunk normal VLANs: noneĪdministrative private-vlan trunk private VLANs: none However, the trunks on both switches are configured with the same values and I don't see any problem here: Link type is point-to-point by default, Peer is STP Number of transitions to forwarding state: 1 Timers: message age 0, forward delay 14, hold 0 Port path cost 4, Port priority 128, Port Identifier 128.129ĭesignated root has priority 24577, address 000d.bce9.2b00ĭesignated bridge has priority 32769, address 8c60.4f1b.9181ĭesignated port id is 128.129, designated path cost 4 Port 129 (Ethernet1/1) of VLAN0001 is broken (Port VLAN ID Mismatch) Hello Time 2 sec Max Age 20 sec Forward Delay 15 secīridge ID Priority 32769 (priority 32768 sys-id-ext 1)Įth1/1 Desg BKN*4 128.129 P2p Peer(STP) *PVID_Inc However, after upgrading the Nexus 5672 from NX-OS 7.0(2)N1(1) to 7.1(0)N1(1), the connection between the Nexus and the Catalyst 3750 is broken - the corresponding port on the Nexus (eth 1/1) is blocked by STP due to a Port VLAN ID mismatch and it chooses itself to be the root bridge:
Everything worked just fine - the link came up and I was able to manage the Nexus using the SVI I created in VLAN1.
I connected one of the switches to our catalyst 3750 Core using trunks on each side. I'm currently in the process of configuring two Nexus 5672 Switches for our Network.