[ewg] Capturing infiniband packets on the wire

Greg Kerr kerr.g at husky.neu.edu
Tue Apr 5 06:39:21 PDT 2011


>  There is NO outbound frame in my ibdump captures:
>   - is that expected behavior ?

When you say outbound frame... specifically what packets are you seeing in 
Wireshark? It should show what 'type' each packet is. Are you not seeing any 
packets labeled 'RC Send First'? Are you only seeing packets labeled 'RC Recv 
...'?

>   - as far as I have understood, the queue pair to which payloads are
>   sent is coded in the IB frame. How come can a program observe frames
>   sent to an other queue pair using its own queue pair ?

The destination QP is coded in the Base Transport Header, specified on page 155 
of the current specification. 

I'm not sure I understand the rest of your question. Are you suggesting that 
you want to write a program to do such a thing, or are you asking how it is 
ibdump can display all packets?

>   - is ibdump relying on Mellanox card specific features ? Is source
>   code available ?

I'm not sure, but I assume the source code is closed and that it rely on card 
specific (or at least driver specific) features. It only runs on Mellanox 
ConnectX®/ConnectX®-2 adapters.

-- 
Greg Kerr
High Performance Computing Lab
Northeastern University



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