[72849] in North American Network Operators' Group
Re: COnfiguration Suggestion - Etherchannel
daemon@ATHENA.MIT.EDU (Robert Blayzor)
Tue Jul 27 23:10:10 2004
Date: Tue, 27 Jul 2004 23:09:37 -0400
From: Robert Blayzor <rblayzor@inoc.net>
To: Mike Sawicki <fifi@HAX.ORG>
Cc: "Richard J. Sears" <rsears@adnc.com>, Nanog <nanog@nanog.org>
In-Reply-To: <20040728024510.GQ87092@HAX.ORG>
Errors-To: owner-nanog-outgoing@merit.edu
Mike Sawicki wrote:
> I would use method #2 above.. L3 FEC produces better balancing
> results as it is flow based, rather than mac-based. I'm not 100%
> certain that using the SVI interface would not produce a proper
> balance, but I doubt it. Using method one I would expect only one
> of the links to be used.
>
> Use method 2 especially if you mean this to be a L3 handoff to the
> customer.
What Mike states is correct about the layer2 vs layer3 load balancing:
http://www.cisco.com/en/US/customer/products/hw/switches/ps700/products_configuration_guide_chapter09186a008007f648.html
Understanding Load Balancing
EtherChannel balances traffic load across the links in a channel 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 either MAC addresses or IP addresses
and either source or destination or both source and destination
addresses. The selected mode applies to all EtherChannels configured on
the switch.
Use the option that provides the greatest variety in your configuration.
For example, if the traffic on a channel is going only to a single MAC
address, using the destination MAC address always chooses the same link
in the channel; using source addresses or IP addresses may result in
better load balancing.
--
Robert Blayzor
INOC, LLC
rblayzor@inoc.net
