6509 throughput issue while testing IPERF

mohd.jaseem · ‎08-12-2010

Core Switch 6509-Throuhput problem:

Action Taken:

Topology of the network:

(NTC)PC---5/2|_6509-1_|3/1---|3560|---MUX---MUX----|_6509-2_|1/12-----PC(DR)

++facing issues when you are performing backups from NTC to Bangalore.

++Replication switches are connected to core switches.

++There is a PC connected to each core switch

++When we are doing a bandwidth test though IPERF from PC on 6509_1 to PC on 6509_2, we face throughput issues.

++when we connect a pc to 3560 and then perform a test to PC on 6509_2 it works fine.

++connected a PC on 3560 and did the test from 6509_1, it worked fine.

Testing is done through iperf.

When we do a transfer from PC on 6509_2 to PC on 6509_1 ,IPERF with 1 session is ok,2 session is also ok but after 3 session there is lot of TCP retransmission

Robert Taylor · ‎08-20-2010

You may want to do some spans to find the culprit for the drops, as thats what it seems like is happening ...

span the egress port of the 6500 on the left, and the ingress port of the 6500 on the Right ... and lets see at which point (or both) we see the missing packets. I assume iperf is putting some ID numbers in the packets so that we can tell when we do not get one successfully across ...?