Hi all On Fri, Aug 03, 2007 at 11:15:52AM +1200, Jonathan Brewer said:
Hi Folks,
We've found in a couple of cases that ICMP packets coming from some address ranges (such as the WIX range 202.7.0.0/25) don't make it through GG.
The WIX block (202.7.0.0/23 - note, it's a 23, not a 25), and all the other NZ exchange blocks, are not advertised internationally unless an ISP is doing so - there have been examples of ISP's accidentally doing that in the past. It's a fairly foolhardy thing to do, and most stop pretty smartly once they realise. Equally, how far ISP's carry the NZIX blocks into their networks is a choice each provider makes - you can't assume domestic reachability from/to that /23. So, really, you shouldn't be asking "why don't GG carry packets originating from 202.7.0.0/23", rather, you should be asking, "why am I originating packets from a range that is intentionally poorly routed". It was relatively common a few years ago for ISP's providing transit services to customers to include a hop within the WIX range. I believe everybody has given up doing that for new connections, but there are still a few ISP's (at least ICONZ, TCL) who have some historical customers connected that way. I certainly wouldn't encourage anybody to do this just to save a few IP numbers - it makes traceroutes look scody, and almost certainly breaks path MTU discovery. Cheers Si