[c-nsp] 3750 etherchannel only using 1 port

Paul paul at gtcomm.net
Wed May 7 15:57:48 EDT 2008


I did the test etherchannel of course and it's working properly, but 
since I am using the cef load balancing (two 0.0.0.0 routes with the 
same cost)  and it's going out two port channels the algorithm for that 
must be exactly the same as the one for the etherchannel, which explains 
why on etherchannel #1 the packets are going out port #1, and on 
etherchannel #2 the packets are going out port #2..   This is a very 
interesting phenomenon :) 

Now I just have to figure out what to do about it..... I Completely 
would not have thought that it would operate like this but I suppose it 
makes sense..  Grr :>
Any ideas?


Paul wrote:
> Oh ho! This gives me an idea..
>
> I'm doing CEF load balancing with multipath over two etherchannels and 
> I think what is happening is that the
> multipath load balancing is using the exact same algorithm as the 
> etherchannel so that it's only sending ips out one port channel that 
> the etherchannel load balancing algorithm picks only one port to use.
>
> This is a bad side effect if that is the case.  I wonder if there is a 
> way to change the algorithm around a bit for either the cef or the 
> etherchannel load balancing in order for this to work properly..
>
>
>



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