Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Announcements

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

Input packet drops on Nexus 1000v

Hello guys,

Could you help me to get the right answer?

description

I get alot of Input packet drops ,

N1K-DC1-01-INT# sh int | i drop

    21999658 input packet drops

    0 output packet drops

    21998884 input packet drops

    0 output packet drops

    46233225 input packet drops

    0 output packet drops

    21999657 input packet drops

    0 output packet drops

....

Uplink mode command is  "channel-group auto mode on mac-pinning"

for example:

port-profile type ethernet DvSUplink

  vmware port-group

  switchport mode trunk

  switchport trunk allowed vlan 8,11,39,88,108-115,149-150,152-159,302

  channel-group auto mode on mac-pinning

  no shutdown

  system vlan 150

  description VLAN 108-115 PRODUCTION

  state enabled

We clear the interfaces ; however ,the  command  show int | egrep -i "ethernet|drop" displays input packet drop again, see below

N1K-DC1-01-INT# clear counters  [31D [J

N1K-DC1-01-INT# show int | egrep -i "ethernet|drop"

  Hardware: Ethernet, address: 0050.56a5.0004 (bia 0050.56a5.0004)

Ethernet3/4 is up

  Hardware: Ethernet, address: 0050.5650.05af (bia 0050.5650.05af)

    50 Input Packet Drops 0 Output Packet Drops

Ethernet3/8 is up

  Hardware: Ethernet, address: 0050.5650.037e (bia 0050.5650.037e)

    55 Input Packet Drops 0 Output Packet Drops

Ethernet4/4 is up

  Hardware: Ethernet, address: 0050.5650.014d (bia 0050.5650.014d)

    55 Input Packet Drops 0 Output Packet Drops

Ethernet4/8 is up

  Hardware: Ethernet, address: 0050.5650.018d (bia 0050.5650.018d)

    55 Input Packet Drops 0 Output Packet Drops

Nexus 1000v:4.2(1)SV2(1.1a)

UCS en version 2.1.3

Vsphere 5.1

Appreciate any help.

Alioune


5 REPLIES

Input packet drops on Nexus 1000v

Hi Alioune,

This is expected behaviour on the Nexus 1000v Ethernet interfaces when the uplinks are configured with MAC pinning.

When using MAC pinning there's no special configuration of the ports on the upstream physical switches and so any broadcast packets are sent by the upstream switches on all uplinks towards the Nexus 1000v switch.

On each VEM of the Nexus there's one uplink interface that is chosen as the Designated Receiver for broadcast traffic, and the function of the DR is to forward received broadcast traffic to VMs within the VLAN. The broadcast traffic received on any other uplinks of the VEM i.e., those that are not the acting as DR, drop the received broadcast traffic on ingress to the VEM.

The drops you're seeing on the uplink interfaces are almost certainly the broadcast traffic being received on one or more non DR uplinks.

Regards

New Member

How can you see which

How can you see which interface is the DR?

Cisco Employee

what is your UCSM versionyou

what is your UCSM version

you can check through CLI

SSH to FI

connect nx

sho platform  software enm  internal  info vlandb id xxx

 

 
New Member

Thanks Ahsan, your command

Thanks Ahsan, your command may work for UCS, but what about Nexus 1000v?  I found this command which is supposed to show the designated receiver, but out output is not what I expect to see.

vemcmd show dr

It says the DR is the port-channel interface.  I expected it to list a member interface, not the port-channel.

Example

Switch# module vem 27 exec vemcmd show dr

BD 7, vdc 1, vlan 3642, 4 ports, DR 561, multi_uplinks TRUE
Portlist:
     17     vmnic0
     18     vmnic1
     49     vmk0
    561  DR

BD 8, vdc 1, vlan 3645, 4 ports, DR 561, multi_uplinks TRUE
Portlist:
     17     vmnic0
     18     vmnic1
     52     vmk3
    561  DR

 

Switch# module vem 27 exec vemcmd show port
  LTL   VSM Port  Admin Link  State  PC-LTL  SGID  Vem Port  Type
   17    Eth27/1     UP   UP    F/B*    561     0    vmnic0 
   18    Eth27/2     UP   UP    F/B*    561     1    vmnic1 
   19    Eth27/3     UP   UP    FWD     562     2    vmnic2 
   20    Eth27/4     UP   UP    FWD     562     3    vmnic3 
   21    Eth27/5     UP   UP    FWD     563     4    vmnic4 
   22    Eth27/6     UP   UP    FWD     563     5    vmnic5 
   49     Veth97     UP   UP    FWD       0     0      vmk0 
   50     Veth98     UP   UP    FWD       0     0      vmk1 
   51     Veth99     UP   UP    FWD       0     0      vmk2 
   52    Veth100     UP   UP    FWD       0     1      vmk3 
(---cut--)

  561       Po25     UP   UP    F/B*      0                 
  562       Po85     UP   UP    FWD       0                 
  563       Po91     UP   UP    FWD       0                 
Cisco Employee

•Each uplink is assigned a

•Each uplink is assigned a SGID based on vmnic number (vmnic0 = SGID 0, vmnic1 = SGID 1, etc)
•Each VM is pinned to a SGID in a round-robin fashion
1060
Views
5
Helpful
5
Replies
CreatePlease login to create content