[c-nsp] Uneven LACP load-balancing

[Brandon Ewing]

On Fri, Nov 12, 2010 at 11:54:03AM -0500, Benjamin Lovell wrote:
> Following up on this. Does the 3560 support etherchannel hash on 
> src-dst-mac and src-dst-ip? This should change up the hash between CEF and 
> etherchannel and prevent a polarization like effect.

No.  Either src-dst-ip or src-dst-mac.  There is no composite of the two.

The puzzling thing to me is, I have identified flows between two IPs, that
examined with "ip cef exact-route" and "test etherchannel load-balance",
SHOULD use the unutilized link.  However, given that 0 traffic is flowing
over the unutilized link, clearly there is something else internally going
on that is not clear to me that is undocumented.

switch#show ip cef exact-route 172.16.79.186 192.168.42.183
172.16.79.186 -> 192.168.42.183 => IP adj out of Vlan100, addr 10.10.1.245

switch#show vlan id 100
VLAN Name                             Status    Ports
---- -------------------------------- --------- -------------------------------
100  uplink1                          active    Po4


switch#test etherchannel load-balance interface po4 ip 172.16.79.186 192.168.42.183
Would select Gi0/51 of Po4

switch#show controller util | inc (^Port|Gi0/51)
Port       Receive Utilization  Transmit Utilization
Gi0/51             1                    0

And I've confirmed via NetFlow that a non-trivial amount of data is exchanged between those two IPs.

-- 
Brandon Ewing                                        (nicotine at warningg.com)
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