[166861] in North American Network Operators' Group
Re: Network topology [Solved]
daemon@ATHENA.MIT.EDU (John Kemp)
Fri Nov 15 17:41:41 2013
Date: Fri, 15 Nov 2013 14:41:29 -0800
From: John Kemp <kemp@network-services.uoregon.edu>
To: nanog@nanog.org
In-Reply-To: <B4BBC561-B7DA-4E67-9271-95BE3511B678@wisc.edu>
Reply-To: kemp@network-services.uoregon.edu
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
I know Carlos did a bunch of work to build this
into Netdot, i.e. discover L2, draw usable graphs.
Here's a link to the last NANOG presentation:
http://www.nanog.org/meetings/nanog49/presentations/Tuesday/Vicente-netdot-presentation-nanog49.pdf
John Kemp
On 10/15/08 7:18 PM, Dale W. Carder wrote:
>
> On Oct 15, 2008, at 1:35 PM, Colin Alston wrote:
>
>> On 2008/10/15 06:29 PM Colin Alston wrote:
>>> Is there any kind of cunning trick to detect standard layer2 switches
>>> along a path without stuff like STP?
>>
>> Apparently there isn't. Lots of people mentioned other tools, the
>> problem there is they have one thing in common which is polling SNMP.
>> I think it scales badly in general.
>
> What is your reasoning behind this claim? I would claim
> quite the opposite compared to CLI or TL1.
>
>> Maybe there should be something (I mean like, someone should come up
>> with a standard :P) to trace switches in a path
>
> I've written a cruddy script that given a seed bridge, scrapes
> L2 information obtained via CDP (I guess it could do LLDP, too)
> and does a breadth-first search through a network. Then I just
> dump that into gnuplot format. Getting the data is easy compared
> to visualization.
>
> A coworker of mine has written script to ask Rapid-STP speaking
> switches about their current topology and builds a graph again
> in gnuplot format.
>
> A more challenging approach would be to scrape the mac forwarding
> tables and stitch things together. This would have to be done
> per-vlan. I think this approach (or similar) might be done by
> Openview's L2 featureset.
>
> Dale
>
> --
> Dale W. Carder - Network Engineer
> University of Wisconsin / WiscNet
> http://net.doit.wisc.edu/~dwcarder
>
>
