U have jumbo frames

Rishav Garg · ‎03-12-2015

We have a netapp storage on our Nexus and we are seeing alot of pks discarded on ingreess. I know that the Nexus does ingress queing so this seems to point to congestion on an egress port. How can I figure out what port is causing the problem or has the congestion?

I looked on Ciscos website but I can't find a good troubleshooting docutment.

qos-group 4
    q-size: 29760, HW MTU: 9216 (9216 configured)
    drop-type: drop, xon: 0, xoff: 29760
    Statistics:
        Pkts received over the port             : 5589330309
        Ucast pkts sent to the cross-bar        : 5504968963
        Mcast pkts sent to the cross-bar        : 86720
        Ucast pkts received from the cross-bar : 0
        Pkts sent to the port                   : 162325
        Pkts discarded on ingress               : 72274627
        Per-priority-pause status               : Rx (Inactive), Tx (Inactive)

Kindly help how to find which egress port is congested due to which ingress discards are increasing (I think this is a backpressure suitation)).

NXOS Version is 5.2(1)

Sebastian Helmer · ‎03-13-2015

U have jumbo frames configured? it is not bad but I just want that u know and want that.

Did you check the interface counters and see any problem..maybe do a clear counter interface before
- sh inter count erro

Is there somewhere a bottleneck, because u are right. ingress drops means there is a congestion on one of the egress..

is it a N7K?

U can check with an elam trigger where your packets are going, if u have redundacy for example..
just google for "N7K elam" u will find that e.g. which help me already to find the exact flow..use it for the module u have in place.

http://www.cisco.com/c/en/us/support/docs/switches/nexus-7000-series-switches/116647-technote-product-00.html

Rishav Garg · ‎03-17-2015

Thanks for your reply..

We don't have any N7K but we have Nexus 5548 UP model. So i checked ELAM doesn't support on N5K.

Kindly tell any other procedure to get to know which egress port is congested due to which ingress discards are increasing..?

Kindly help here...

packet discards