Input packet drops on uplink port-profile

Question

Hi,
I'm using Nexus 1000v and vSphere 5.1;
I just migrated some physical servers to VM, and I have some weird reporting issues;
Just to make sure it wasn't a network issue they asked me to verify if anything was overlooked on the Nexus side of things;
Everything checked out, but I'm seeing a lot of input packet drops on the physical ports of the system uplink port-profile;  I doubled checked the configs on the VSM and the Catalyst stack and all is configured properly;
should I be concerned about these Input packet drops that I'm seeing on the VSM on the physical interfaces of my uplink port-profile?  If so, could it be the NICS in the ESX host that could be the issue?
Any feed back would be appreciated;
Thanks.

Answer 1

I have the same symptomps on 3 different Nexus 1000v. All 3 run the same version  - 4.2(1)SV2(1.1) VMware is 5.0 sp1 and the hardware for ESXi hosts is more or less the same (At least server blade model and CNA).
We have tried to use vempkt to capture traffic but no traffic is captured if we filter on drops even though the counter on the port-channel and member Ethernet interfaces increase. On the hosts we tried vempkt we see about 20 drops per second. Here is some info. I have removed some irrellevant stuff.
NRK-VSM-001# show int po 14
port-channel14 is up
Members in this channel: Eth6/3, Eth6/4
6172 input packet drops <- Increases
NRK-VSM-001# show mod 6
Mod  Sw                  Hw     
6    4.2(1)SV2(1.1)      VMware ESXi 5.0.0 Releasebuild-1024429 (3.0)    
Mod  Server-IP        Server-UUID                           Server-Name
6    10.16.1.12       4c4c4544-0034-3010-8036-b4c04f33354a  nrk-vi01-h07.nt.se
FROM The ESXi
~ # vemcmd show port
  LTL   VSM Port  Admin Link  State  PC-LTL  SGID  Vem Port  Type
   19     Eth6/3     UP   UP    F/B*    305     0    vmnic2 
   20     Eth6/4     UP   UP    F/B*    305     0    vmnic3 
~ # vempkt show capture info
Stage : Drop
     LTL : 305
    VLAN : Unspecified
    Filter : Unspecified
Even if we let the capture run for several minutes we see no drops. I set it to capture 31 packets.
~ # vempkt show info
                 Enabled  : Yes
    Total Packet Entries  : 0       <-  Never increases even if the capture is running filtered like above
  Wrapped Packet Entries  : 0
     Lost Packet Entries  : 0
  Skipped Packet Entries  : 560145
Available Packet Entries  : 14169
     Packet Capture Size  : 88
     Packet Capture Mode  : Un Reliable
Stop After Packet Entry  : 31
In our case, could the input drops depend on that we allow vlans from the upstream hardware switch to the VEM that do not exist on the N1000v and that this is the reason we can not capture the dropped packets?
Any ideas?
PS: We see drops on uplinks on all VEMs