Route processor packet drops

Unanswered Question
Jul 5th, 2007


I have an problem with two servers that are trying to do linkloop to each other and fails. Both are connected to the same switch Catalyst 6509 on the same module X6748-GE-TX. I checked the interfaces are found overrun packets and input queue drops. When I checked detail statistics I found that I see qos0InLost packets. Moreover I see that the input queue drops come from RP (see attachment)

Could You tell me which packets are examine by RP and what might be causing this drops?

Thanks in advance for any ideas.



I have this problem too.
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Edison Ortiz Thu, 07/05/2007 - 05:17

I'm assuming you have a Sup720, correct ?

Can you post the output from typing

show module


show fabric


michal.grzelak Thu, 07/05/2007 - 05:43


Thx for an replay. I don't think it is a switch performance problem, I would rather think that the server is using some type of packet that can't be switched by route processor. The ports are on the same switch\module 8 and it is access-layer switch (no routing defined).

Also please take a look at server errors in attachment.



Edison Ortiz Thu, 07/05/2007 - 06:20


You are correct on stating the switch performance is not an issue here. I'm not familiar with the procedure you are trying to undertake at the servers but perhaps the RP does not understand the 'linkloop' mechanism between the 2 servers.

The Route Processor (RP) will take care of packets not identified by the Switch Processor (SP).

michal.grzelak Thu, 07/05/2007 - 22:42


Could You tell me what kind of packets are held by RP and which by SP? Maybe that will help me in finding a problem.

Linkloop is just a HP-UX tool to test network connectivity using layer2. I is used on our servers and there were no problems befere with that.



Edison Ortiz Fri, 07/06/2007 - 04:15

When you send a packet, it first goes to the Switch Processor (SP) and the SP checks if the destination is on the mac-address-table. If it isn't will be send to the Route Processor (RP) as a last resort.


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