Catalyst 6513 and Txpause

bfledderjohn · ‎02-23-2007

We have the 6148-GE-TX cards in our 6513 and a recent conversation with a Cisco tech made me learn that these cards are oversubscription linecards. Buffers are shared among 8 ports and it is recommended to spread high end servers out and try to keep them off the same buffer. Does anyone have any insight on this? Should I follow these guidelines of not having high end servers sitting next to each other on the switch? What about flow control? Should I set this to send on and receive on, after making sure the server side setting is that same as well?

Thanks.

purohit_810 · ‎02-23-2007

See flow control as such, i don't think required for 6513 switch, reason it has laready high processing power and High end server has that machanisam.

We should not have to worry about flow control, unless you cannot observe any packet loss.

Are you facing any problem related to packet loss?? or regarding communication??

Racommanded is that don't disturb switch default configuration.. until you have essantial.

Regards,

Dharmesh Purohit

poulid · ‎02-23-2007

We're having the same issue with a 48 port line card for our 4507R. I opened a call with TAC because we are seeing a lot of Rx-No-Pkt-Buff errors. These errors only seem to increment during our nightly backups.

The Cisco Engineer told us the same thing, that the 8 port groups share a common ASIC, so only plug a server in every 8 ports. I enquired about flow control as well, and here was the Engineers response

"Basically if you enable flow control will be a workaround but still I don?t suggest doing it since the device or blade that will be doing the flow control will be flooding its buffers and will start having the same issues"