This will provide a view from the street, it will display exactly what your router knows.
Route servers / Looking Glass –This is your basic external view. Log in and see what other ASNs know about your routes. Critically important during those “something is on fire” times mentioned above. They are maintained by a myriad of entities and positioned all over the globe.
BGPmon –A project by Andree Toonk. Allows for the automatic discovery and monitoring of prefixes, alerting on many, many attributes such as prefix hijacks. Free and commercial plans available, but the commercial plans are far more feature rich and well worth it if you monitor large amounts og BGP.
Peermon –Part of the new and improved BGPmon. Allows for the on-demand monitoring of prefixes within your network. Very useful for viewing as-path changes of destination networks for long term troubleshooting.
RouteViews – Great project out of U of Oregon that was (is?) run by the groundbreaking David Meyer of OpenDaylight (and many other things) fame. Peers with networks and records routing changes, allows for public query and has vast historical data.
bgplay - Great visualization tool for tracking routing, as-path and prefix announcement changes. This is part of the routeviews project and utilizes their vast historical data. L=It currently acks IPv6 support and I;m unsure if it is maintained anymore.
Router Proxies – This has been a big thing int he R&E world for quite some time. Other entities may offer it, it’s similar to a looking glass but more easily configured to allow or disallow different show commands. The code is open source and pretty easy to hack new commands into or adapt to new platforms (if I can do it anyone can).
Lookup tools such as whois. I find that looking uo ASNs and networks against the ARIN, RIPE and other RIRs is very handy as a starting point. using CLI commands such as “whois -h whois.arin.net 1224″ would display useful information.
Very handy for prefixes and ASNs. There are also service like the Team Cymru whois server that can display date/time based information for forensics and to provide IP to ASN mappings. Also very handy. I believe this code is also open source.
IRR Toolset. Extremely handy for automation of routing policy configuration. I found it a tad painful to set up but it is a useful toolkit.
Notable Mention: NLNog RING. – This is a trust based unix host that provides a large variety of services to those that qualify for participation. Very handy when looking for an on-net perspective.
Notable Mention / Shameless Plug: perfSonar toolkit. In addition to thewell known performance testing tools, PS provides things like reverse traceroute and other handy networking widgets. It also has a far lower barrier of entry than the NLNog RING.
There are obviously more ways to do this and there are possibly better ones, too. This is how I’ve done it for a long time and it has mostly worked for me. I had to learn most of this by trial and error so I thought it maybe useful to throw it all together into one place for future reference.