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New Member

show counters on Cat65xx (catOS 7.4(3))


I have actually a trunk and GEC with 2 links between two catalyst 6509.

I've searched for the signification of the field " rxTotalDrops " (show counters command) on the site and they say it's probably a CBL problem (packet receive with a vlan non autorized on the trunk) if no over errors are visible.

The problem is that :

- No other errors are visible (CRC, frame size...) all counters are at "zero",

- All vlan are authorized on the port (STP "forwarding state for all),

- The command "set errordetection portcounters" is disable.

Does anybody have an idea of the possible cause for the incrementation of this counter ?

Thanks in advance

  • Other Network Infrastructure Subjects

Re: show counters on Cat65xx (catOS 7.4(3))

The followinf could be the reasons for incrementing rxTotalDrops.

- Bad packet due to CRC error,coding violation,sequence error, etc.

- CBL drop

- Invalid encapsulation

- Drop due to broadcast suppression

- Drop because packet length is less than 64 or greater than 1518

New Member

Re: show counters on Cat65xx (catOS 7.4(3))

The 6500 series use a store and forward technology. As a result any bad frames should be dropped. These are rx drops so if the frame is bad it's occuring after being transmitted from the other 6500 or one of the ports is having a problem.

You may want to check your GEC configuration as well. You can configure separate transmit and receive ports on a fastetherchannel. If one side is configured differently from the other you may have found the culprit.

Good luck.

New Member

Re: show counters on Cat65xx (catOS 7.4(3))

I thought I'd elaborate:

Individual links on a GEC can be configured for transmit or receive only. If one side is set to transmit and receive while the other only transmit or receive rxTotalDrops will increase. If running CatOS use clear count {Blade/Port} to clear the counters. Generate some traffic across the link and see if your counters rxTotalDrop increase.

New Member

Re: show counters on Cat65xx (catOS 7.4(3))

Hi ,

I don't find any command to configure a link for "transmit" or "receive" only in a GEC on CatOS.

Can you give me the commands or links related to these parameters ?

If I clear the counters, it increases once more

Thanks in advance

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