Making BGP changes can be a daunting tasks and when there’s an error during BGP changes the effects can be felt for an entire data-center over an extended period of time. As any Networking Engineer or Networking Administrator can tell you, it takes time for BGP to converge. It’s not as quick as OSPF or even RIP – after all imagine updating the entire routing-table for the internet every time someone makes a change.
Looking Glass Server:
That’s why a lot of providers have given us a tool that I use and it’s called a Looking Glass server. My favorite Looking Glass Server is the Hurican Electric Looking Glass Server located here – http://lg.he.net/
There is also a ‘Packet Clearing House’ Looking Glass https://prefix.pch.net/applications/lg/ that give you the option of Looking Glass servers around the world.
What is a Looking Glass Server?
What exactly is the magic Looking Glass Server? It’s simple, all that the Looking Glass Server does – is show you the routing table of an ISP through a web page. Essentially, it give you the ability to look at the BGP routing table of their edge routers. Pretty neat!!
Notes:
- The type of routing that is referenced here is eBGP. This is used with ASN numbers both on the client side of the peering and the provider side of the peering.
- Looking Glass servers only give you information on what the provider has, if you are homed to different providers there may be delays in routing exchanges.