From: James (james@towardex.com)
Date: Fri Oct 22 2004 - 21:25:12 GMT-3
On Fri, Oct 22, 2004 at 08:17:58PM -0400, Ian Stong wrote:
> Does that apply to span port traffic as well? I.E. if I use a 3550 and
> setup a span port to monitor traffic for IDS, DOS, etc - are there
> potentially packets it won't see? I suppose it depends on whether the
> switch is configures as strictly L2 or as L2/L3 as well???
No... AFAIK, span is totally different and lower level of complexity than
layer3 forwarding operations. I'm using a 3550 w/ SPAN monitor right now
in fact, and have no problem with it.
-J
>
>
> Ian
> www.ccie4u.com
>
>
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
> James
> Sent: Friday, October 22, 2004 8:07 PM
> To: ccie2be
> Cc: P729; Anthony Pace; ccielab@groupstudy.com
> Subject: Re: DEBUG IP Packet on a CAT-3550????
>
> On Fri, Oct 22, 2004 at 07:57:40PM -0400, ccie2be wrote:
> > Hey Mas,
> >
> > As you can see from the debug output below, I'm not seeing any ip unicast
> > traffic, but should I expect the debug command to work the same way on a
> > 3550 as a regular router?
>
> Hi Tim,
>
> Unfortunately, not necessarily. The 3550 will only show process switched
> packets (mostly),
> which are either locally generated packets or packets arriving into the
> receive adjacency
> queue for processing by the CPU (in other words, locally destined packets).
>
> Transit packets are ASIC-forwarded (CEF), and 3550 has the tradition of not
> keeping checks
> and balances of what it moves at layer3 level, when things are hardware
> forwarded.
>
> HTH,
> -J
>
> --
> James Jun TowardEX Technologies,
> Inc.
> Technical Lead Network Design, Consulting, IT
> Outsourcing
> james@towardex.com Boston-based Colocation & Bandwidth
> Services
> cell: 1(978)-394-2867 web: http://www.towardex.com , noc:
> www.twdx.net
>
> _______________________________________________________________________
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-- James Jun TowardEX Technologies, Inc. Technical Lead Network Design, Consulting, IT Outsourcing james@towardex.com Boston-based Colocation & Bandwidth Services cell: 1(978)-394-2867 web: http://www.towardex.com , noc: www.twdx.net
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