[ALUG] Mostly-OT: Strange ADSL issues

[Wayne Stallwood]

This is all pretty weird stuff I must admit

FYI pinging large packets to more-solutions.co.uk worked for me with
very consistent results. I tried 1473 and larger with no problem and a
quick reply.

It's interesting that you can get the ssh banner page with telnet, I
guess it is the fragmented packet thing not working that is stopping a
proper ssh connection from being forged, the banner page is probably
less than one transmission unit but a full key exchange to get to the
login prompt probably isn't.

So it sort of looks like anything that involves data exchange over your
MTU size fails, which sort of points to a very broken IP stack
somewhere. But given that you have got this on two different machines,
with two different connections via two different routers I can't think
why. Are there any commons between machines, same kernel ? same firewall
configuration ?

I have a larger box of straws somewhere we can try clutching at..bear
with me while I try to find it :-)

Ahh here we go, extra large Tesco Value pack....Can you ping from the
linux router ? Can you do the ping large packet test from there to
isolate everything else ?