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 > >