From: phase90 (phase90@comcast.net)
Date: Tue Feb 01 2005 - 22:22:15 GMT-3
So if I read this correctly, a packet going through 2 routing hops and a
2000 line [ turbo ] ACL
has the same latency as a packet going 0 hops via connected Vlan interface.
I think you've been
talking to the Cisco marketing group too long!
phase90
----- Original Message -----
From: "Balaji Siva" <bsivasub@gmail.com>
To: "Conte, Charles" <Charles.Conte@nasdaq.com>
Cc: "phase90" <phase90@comcast.net>; "asadovnikov"
<asadovnikov@comcast.net>; <ccielab@groupstudy.com>
Sent: Tuesday, February 01, 2005 7:38 PM
Subject: Re: Simple Design Question
> Yes that is correct. There is no speed penalty for L2 or L3 switching.
> For example on cat4k, it is all done in hw asic and if the packet is
> not routed, that function is "no opearation".. So whether you turn on
> routing/acl/qos, it all is same.
>
>
>
>
> On Tue, 1 Feb 2005 19:34:32 -0500, Conte, Charles
> <Charles.Conte@nasdaq.com> wrote:
> > 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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