Etherchannel load-balancing with Sup720/6509 IOS.

[jkeeffe]

I have several 10gb etherchannels fanning out from two 6509 core switches to some multiple 6509 distribution switches. All 6509s have Sup720 and running 12.2(18) IOS. The etherchannels are made up of 2 10gb interfaces each. The distribution 6509s feed access layer 6509s where dozens of Unix and MS servers are located, and thousands of users access these dozens of servers.

What is the best way to load balance these etherchannel links so I can best utilize the 10gb interfaces?

[glen.grant · Accepted solution]

Probably your best bet if you have a lot of different ip's coming down the etherchannel is to set them to load balance using the source -ip address , you will probably get more equal distribution that way . This Cisco's explanation.

An EtherChannel balances the traffic load across the links in an EtherChannel by reducing part of the binary pattern formed from the addresses in the frame to a numerical value that selects one of the links in the channel.

EtherChannel load balancing can use MAC addresses or IP addresses. With a PFC2, EtherChannel load balancing can also use Layer 4 port numbers. EtherChannel load balancing can use either source or destination or both source and destination addresses or ports. The selected mode applies to all EtherChannels configured on the switch.

Use the option that provides the balance criteria with the greatest variety in your configuration. For example, if the traffic on an EtherChannel is going only to a single MAC address and you use the destination MAC address as the basis of EtherChannel load balancing, the EtherChannel always chooses the same link in the EtherChannel; using source addresses or IP addresses might result in better load balancing.