From: Jonathan V Hays (jhays@jtan.com)
Date: Sun Nov 02 2003 - 11:55:59 GMT-3
Howard,
Yes, Cisco has defined L3 EtherChannel, as those of us studying for the
CCIE Lab are well aware from reading and re-reading the 3550 Software
Config Guide. Take a look:
http://www.cisco.com/univercd/cc/td/doc/product/lan/c3550/12119ea1/3550s
cg/swethchl.htm#1024682
Jonathan
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Howard C. Berkowitz
Sent: Sunday, November 02, 2003 9:36 AM
To: ccielab@groupstudy.com
Subject: RE: Dumb Question but will ask
I'm confused. Has Cisco, somewhere, actually defined L3 EtherChannel?
If it has, it's yet another case of marketingspeak, creating
meaningless concepts such as L3 vs. L2 switches.
If it hasn't, and we are speaking of load distribution based on L3
information, we are speaking of a normal IOS function. Let me repeat:
load sharing has nothing to do with the routing protocol. You can
load share among static routes.
At 8:26 AM -0600 11/2/03, Mike Williams wrote:
>If I'm not mistaken, you can use the source IP and dest IP addresses to
>determine which link in a L2 etherchannel that traffic will take. So
>even if you have a L2 etherchanenl between 2 routers, the traffic can
>balance over the links (in proportion to the distribution of the
>source/dest addresses).
>
>Mike W.
>
>-----Original Message-----
>From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
>Ryan Cheng
>Sent: Sunday, November 02, 2003 1:25 AM
>To: Shafi, Shahid; ccielab@groupstudy.com
>Subject: Re: Dumb Question but will ask
>
>
>Hi Shahid,
>
>Etherchannel is to make 2 or many physical links to be a logical link,
>but the question comes, how to load-share the traffic into each link?
>
>L2 Ethernet: it makes use of the L2 information (e.g. Ethernet DA and
>SA) as a matching criteria, says any traffic which has a different DA
>and SA in the ethernet header will be flowed into different physical
>link
>
>L3 Ethernet: in contrast, the L3 information (e.g. destination and
>source IP
>address) is used in this case
>
>If you are using a L2 ethernet channel between Routers, the
load-sharing
>won't work since all traffic between the routers have a fixed Ethernet
>DA and SA.
>
>Hope my reply is useful.
>
>Regards,
>Ryan
>
>----- Original Message -----
>From: "Shafi, Shahid" <sshafi@qualcomm.com>
>To: <ccielab@groupstudy.com>
>Sent: Sunday, November 02, 2003 8:40 AM
>Subject: Dumb Question but will ask
>
>
>> Hi Guys,
>>
>> A stupid one but I'll ask though I think I know the answer: What is
>> the difference between layer2 and layer 3 etherchannel? What wont
work
>
>> if I use Layer 3 Etherchannel between switches? VTP?? What is more
>> efficient and why?
>>
>> Any input is great!
>>
>> thanks
>>
>> Shahid
>>
>>
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