RE: ether channel load balancing

From: Jared Scrivener (jscrivener@ipexpert.com)
Date: Wed Feb 11 2009 - 14:47:58 ARST

Hey Roger,

I read through (probably the same document as you) and my interpretation of
"routed IP traffic" infers that it is essentially doing SRC-DST-IP if you
use the SRC-MAC mode and if the source 3550 had to do IP routing of the
packet and was forwarding it over a Port-Channel interface.

I'm not sure if that is what they are saying (the explanation in the
document is too brief), and can't recall labbing that up on 3550's (I've
been using 3750's and 3560's for the last few years worth of deployments).
I'd suggest grabbing a couple of 3550's if you have some, checking it out
and letting us know. :)

Cheers,

Jared Scrivener CCIE3 #16983 (R&S, Security, SP), CISSP
Technical Instructor - IPexpert, Inc.
Telephone: +1.810.326.1444
Fax: +1.810.454.0130
Mailto: jscrivener@ipexpert.com

-----Original Message-----
From: Roger RPF [mailto:rpf@bluemail.ch]
Sent: Wednesday, 11 February 2009 7:28 AM
To: 'Jared Scrivener'; 'BALA'; ccielab@groupstudy.com
Subject: AW: ether channel load balancing

Hi Jared,

In this case, which mode would you use if the switches are 3550's? They only
provide source or destination mac address loadbalancing.
Switch 2 learns only one mac address, the one of BB2, so how can he
differentiate?

R1 <> SW1 <> SW2 <> BB2 ---clients

In the DocCD under the 3550 they write:

"When source-MAC address forwarding is used, load distribution based on the
source and destination IP address is also enabled for routed IP traffic"

But in our case, what does that mean? Does SW2 look in the payload of the
frame? I mean, for switch 2, this traffic Is only switched?
Maybe I missunderstand something....

regards

Roger

-----Urspr|ngliche Nachricht-----
Von: nobody@groupstudy.com [mailto:nobody@groupstudy.com] Im Auftrag von
Jared Scrivener
Gesendet: Dienstag, 10. Februar 2009 14:31
An: 'BALA'; ccielab@groupstudy.com
Betreff: RE: ether channel load balancing

Hey Balavignesh,

Src-dst-ip will give you the best load balancing if applied on both
switches. This will cause the switches to load balance based on a hash of
the source and destination IP for traffic in both directions. For
documentation, check out the 3560 Configuration Guide on the Cisco website.

Cheers,

Jared Scrivener CCIE3 #16983 (R&S, Security, SP), CISSP
Technical Instructor - IPexpert, Inc.
Telephone: +1.810.326.1444
Fax: +1.810.454.0130
Mailto: jscrivener@ipexpert.com

-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of BALA
Sent: Tuesday, 10 February 2009 1:03 AM
To: <ccielab@groupstudy.com>
Subject: ether channel load balancing

Hi GS,

I've a query reg etherchannel, pls can someone help me understand better.

Router_1 connected to SW1 (3560) and BB2 connected to SW2 (3560). Both
switches have L2 etherchannel between them. If Router_1 is servicing clients
connected to BB2, what is the best load-balancing method.

R1 <> SW1 <> SW2 <> BB2 ---clients

Answers:

SW1 - dst-mac
SW2 - src-dst-ip

Is this correct? I am also looking for a good documentation on etherchannel
load-balancing, if any of you come across, pls share it to the group. 

-- 
Thanks & Regards

Balavignesh R
CCNP CCSP CAWLANFE
JNCIS - M - FRW JNCIA - SSL - WX - IDP

Blogs and organic groups at http://www.ccie.net

This archive was generated by hypermail 2.1.4 : Sun Mar 01 2009 - 09:44:10 ARST