Can anybody provide any tips on troubleshooting bandwidth related performance on a Cat 4500.
I have implemented QoS for a customer on a campus network with the core devices hanging off of a Cat 4507R with Sup V cards. However, the customer has experienced numerous occasions when traffic for some applications has showed signs of a significant reduction in bandwidth. Possibly it's down to the QoS .. but I need to prove otherwise.
To troubleshoot this I have been looking at all the key interfaces and checking the 4 Qs to see if there are drops.
There are no packet drops occuring so it's proving difficult to blame this on QoS.
The core 4500 switches are running 12.2(40)SG and 12.2(25)EWA10.
Apart from show interface x/y counter detail does anybody know any other counters I should be checking for dropped packets?
Are there any known bugs that imply packets are dropped without them being counted, I haven't found any?
The traffic in question is traversing GRE tunnels at different points in the infrastructure so could this be relevant?
Some of the cards that are receiving the largest taffic flows are blocking cards with an 8:1 ratio, so the inidividual queue allowance is only 31.25Mbps. However, as I don't see any drops I can't see a need to up the default values and the larger traffic flows are actually incoming, not outgoing on these blocking ports. As I understand it the Rx side of the cards does not have 8:1 contention, only the Tx side.
Any pointers for something I may have missed most appreciated!