From: Conte, Charles (Charles.Conte@nasdaq.com)
Date: Tue Feb 01 2005 - 21:34:32 GMT-3
Hello Phase,
My reason would be to avoid spanning-tree. With Layer 3
switching there is practically no difference in latency. Spanning-tree
is a lot harder to troubleshoot in situations of a loop. I like the
document below on how it talks about some aspects of spanning tree. I
guess everything has the "it depends" attached to it. :)
http://www.cisco.com/en/US/tech/tk389/tk621/technologies_tech_note09186a
00800951ac.shtml
CISCO DOCUMENTATION:
High-end Cisco Layer 3 switches are now able to perform this second
function, at the same speed as the Layer 2 switching function. There is
no speed penalty in introducing a routing hop and creating an additional
segmentation of the network.
-----Original Message-----
From: phase90 [mailto:phase90@comcast.net]
Sent: Tuesday, February 01, 2005 7:17 PM
To: asadovnikov; Conte, Charles; ccielab@groupstudy.com
Subject: Re: Simple Design Question
Yes but what if your access switch / router is one hop from your core,
why
would you route that hop and have the additional latency in the routing
process?
Jerry
----- Original Message -----
From: "asadovnikov" <asadovnikov@comcast.net>
To: "'Conte, Charles'" <Charles.Conte@nasdaq.com>;
<ccielab@groupstudy.com>
Sent: Tuesday, February 01, 2005 12:57 AM
Subject: RE: Simple Design Question
> I like the approach. If access switches are L3 capable you should run
them
> as routers not switches. Although there are always corner cases when
L2
may
> be better option, I strongly agree that benefits of avoiding L2
generally
> greater then any potential downside.
>
> Best Regards,
> Alexei
>
>
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf
Of
> Conte, Charles
> Sent: Monday, January 31, 2005 7:29 PM
> To: ccielab@groupstudy.com
> Subject: OT:Simple Design Question
>
> Hello,
>
>
>
> If MSFC's are available at the access-layer, can anybody
> tell me why we wouldn't run L3 to the access layer if the primary and
> secondary access switches are available in convenient locations? Also
> for the attached gifs can anybody provide any opinions on why one
> wouldn't extend L3 to the access instead of having L2 only Access
> switches [Example 1 L3] V.S. [Example 2 L2]? I like avoiding L2 in
any
> situations that I can. I can understand if the requirement is to have
> the vlan available at every switch to go with example 2, but if not it
> wouldn't make sense to extend L2 everywhere. Any opinions
appreciated!
> Thanks!
>
>
>
> Charles
>
> [GroupStudy removed an attachment of type image/gif which had a name
of
> example_gif_2.gif]
>
> [GroupStudy removed an attachment of type image/gif which had a name
of
> example_gif_1.gif]
>
>
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