[c-nsp] Load balancing on Portchan.

[mb at adv.gcomm.com.au]

Quoting Peter Rathlev <peter at rathlev.dk>:

> On Fri, 2011-07-29 at 14:32 +1000, mb at adv.gcomm.com.au wrote:
>> Have 2 100Mb eth ports in portchan, and 1 port seems to be doing all
>> the receiving:
>
> Keep in mind that ether-channel load-sharing is a transmit function. If
> one switch receives an uneven load the fault lies in the other end. In
> your case it's ESW01 (the 2950) that doesn't load-share adequately.
>
> The only thing you can do is to try changing the algo in the 2950 with
> the global config command "port-channel load-balance dst-mac". This
> might or might not give you better sharing. The 2950 is rather limited,
> accepting only dst-mac or src-mac.

Thanks Peter - Yes, the 2950 is limited...it will be replaced in the 
next couple of months with a 3560

> What kind of traffic traverses this link? Maybe there's another way to
> split up the load.
>

Traffic is a mix of inet/vrf...the main culprit is a backup service 
that replicates basically 100% of the time at whatever bandwidth is 
allowed...potentially moving there vlan to a dedicated trunk would 
help, but id prefer to have the portchan used...if I cant, then ded. 
trunk, then go gbit between the switches when we upgrade the 2950 to a 
3560.





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