Network topology [Solved]

David W. Hankins David_Hankins at
Wed Oct 15 22:06:04 UTC 2008

On Wed, Oct 15, 2008 at 08:35:33PM +0200, Colin Alston wrote:
> 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. I was hoping to find a more intelligent way of, I 

I don't know what scaling parameters you're looking for.  The tool
I wrote to recursively traverse Cisco CDP caches via SNMP, from ~7
seed routers, autodetected the interconnections of a ~100 node network
(back in 1998) in just seconds (I think it was 3, but that was ten
years ago).

Using SNMP.

It didn't strain our P90 it was running on, nor the network.

People often do SNMP wrong (one PDU per packet, single-threaded
transmitters, etc).

> Maybe there should be something (I mean like, someone should come up with a 
> standard :P) to trace switches in a path... Problem is I think even then 
> the simple devices won't bother to support it.

Or if they do, they'll do it wrong.  They can't even get ifDescr

Ash bugud-gul durbatuluk agh burzum-ishi krimpatul.
Why settle for the lesser evil?
David W. Hankins	"If you don't do it right the first time,
Software Engineer		     you'll just have to do it again."
Internet Systems Consortium, Inc.		-- Jack T. Hankins
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