Andrew - Supernews <andrew@supernews.net> wrote:
"Per" == Per Gregers Bilse <bilse@networksignature.com> writes:
Per> But that wasn't really the point. If I telnet to all border Per> routers and do 'sh ip b' I can get all tables too; likewise if I Per> have a starting point and do a lot of LS traceroutes; and maybe Per> even via SNMP (haven't checked what various MIBs support).
You can get the received routes via SNMP. I've done this manually on occasion for the purposes of doing "what-if" analysis of potential traffic plans - take a dump of all available external routes via SNMP, apply to that the proposed policy with regard to selecting the best route, then correlate the resulting route choices with known traffic statistics to determine the resulting utilisation levels of each external link. This has proven useful in a number of situations where radical changes to external routing were being made, to avoid unexpectedly overloading particular links.
I would had liked to had been able to have done such things in the past. I was thinking about having a go at writing something, but it's not like I have enough time as it is, and our network isn't really big enough to warrant it. Though I am interested in what tools already exist to support this (more out of curiousity than need). A quick google search threw up a couple of research papers and IP/MPLSView (www.wandl.com), but I presume others on this list will know of more? Sam