[ALUG] Mostly-OT: Strange ADSL issues

[Adam Bower]

On Sat, Oct 07, 2006 at 11:04:44PM +0100, Mark Rogers wrote:
> 
> Explain that! Snide comments about W2k vs Linux I can come up with
> myself! I need to bring a Linux box back home to try, but when I've sent
> this email I'll reboot this PC with a LiveCD and see whether that's better.

Perhaps the W2k box is setting a DNF (do not fragment) or something so
the router is just dropping the packet? Was that ping running over the
vpn?

> > Nope, you shouldn't need to adjust the PC settings at all, the router 
> > should do the fragmentation (although, what routers are you using, I
> > find it strange that you've found something with an "odd" default? 
> 
> I'm sure 1500 is a very common default! Which routers have you found
> with defaults of 1458?

Anything Netgear, Speedtouch USB modems all seem to default to 1458 with
Windows, a couple of brands I forget but I think possibly Dlink, Dynamode 
and 3com. It would be quite easy I guess given how many consumer routers
are out there to find plenty that are set to 1500 by default.

> Of-course I have to be open to the possibility that the problems at home
> and at work have completely different causes, even if the symptoms are
> similar.

Very possibly, try perhaps using ping and setting do not fragment bits
and see what happens. I don't really have too much recent experience of
fiddling lots with the innards of tcp/ip so i'm a bit out of ideas for
now. I'll try re-reading the thread when I feel less ill perhaps.

Adam
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