I had recently ran into an interesting issue with the nexus 1000v switch. After upgrading from 4.2(1)SV1(4a) to 4.2(1)SV1(5.1). Uplink ports are not reporting VLAN IDs correctly when viewed from the VSM->Uplink->Ports tab->VLAN-ID Column. However, the VLAN IDs ARE reporting correctly on the individual VM Distributed PortGroups (VSM->DV-PortGroup->Ports tab->VLAN-ID Column). Here is how the DV Uplink Port Group looked like:


And here is how the DV Port Group looked like:


We grabbed a show tech-support svs from the N1K. More information on what a show tech-support svs is, can be found at the following cisco web-page. From the logs we saw the following messages that corresponded to the DV Uplink port Group:

Event:E_DEBUG, length:351, at 951023 usecs after Fri Apr 13 14:46:54 2012
[102] msp_vppm_handle_port_profile_update_resp(434): (ERR) profile DV_Uplink_PG update failed: Syserr code: 0x41b1001d,
user string:
internal string:

We contacted Cisco and they had identified a known bug on the N1K. If you have cisco account you can check out bug CSCtz24512