Clarification on what Dribbles are for an Ethernet port.

[pciaccio]

On my Fast Etehrent port I am noticing alot of packets coming in with Dribbles detected.. What does this mean??

2361 input packets with dribble condition detected

[Bobby Thekkekandam]

Hi,

A frame that is defined as a 'dribble' is one that is greater than 1518 bytes but can still be processed. This could point to a problem where the Inter-Frame Gap is too small or non-existent such that two frames join together. Generally, these are forwarded, but some platforms will drop these frames.

Also, this is documented here:

http://www.cisco.com/univercd/cc/td/doc/cisintwk/itg_v1/tr1904.htm

-Bobby

HTH, please rate helpful posts.

[pciaccio]

Can you advise as to what might cause Dribble or the Interpacket gap issue??

[pciaccio]

Has anyone experienced dribbles on their Fast Ethernet interface. What might cause this. My first response was that the interframe gap is too small. What might cause the interframe gap to be too small???

[Bobby Thekkekandam]

Hi,

I missed your previous reply. IPG issues are one potential cause, but not necessarily what is happening in your case. an IPG problem could be caused by a flaky Ethernet PHY, or some other physical problem.

Ultimately, whatever is causing the dribbles is on the other end of the router that is reporting it. If the connected device has been there for a while without seeing this problem, you could have a failing/marginal Ethernet port or cable (theoretically a dribble could be caused by crosstalk on a twisted pair).

If you have a switch connected to this fast ethernet interface, you may be able to catch frames with the dribble condition in a span session, which should shed some more light on it.

HTH,

Bobby

[pciaccio]

Thanks for the response. I did not get an E-Mail for this discussion when you sent your reply. I just happened to look at it and saw your response. I will check the port via SPAN. The port in question is a new card that I just installed in my 7513 router.Possibly I hstill have a faulty board or faulty switch port or bad cabling...Thanks....