packet loss through Nexus 7000

[jkeeffe]

We're experiencing slowness with traffic gonig through a Nexus 7000 running 6.0.3.  We swapped out a 6509 for the Nexus and the slowness started at that time.

When I ping from the Nexus to an IP address (I've tried several IPs, some being many hops away, others just one hop away) I get packet loss. If I ping the same IP addresses from a non-Nexus network switch, there is no packet loss.  The packet loss percent increases as the ping size increase. Here's how that shows up:

Ping size in bytes      Packet loss

100                              0%

150                              0%

175                              1%

200                              1%

300                              2%

500                              3%

800                              4%

1100                             6%

1400                             7%

Any clues as to what could cause greater packet loss as the packet size increases?  Bad cable or interface?

[Dale Miller · Accepted solution]

It sounds like your hitting CoPP. Nexus be default has the CoPP policy applied to the control plane. It will limit ICMP under the management class to about 130 Kbps. To verify you can review the CoPP policy using the following command:

switch#show policy-map interface control-plane

To test, clear the copp statistics with the command below and run your ping tests again and verify.

switch#                                   clear copp statistics

HTH,

Dale