[33764] in North American Network Operators' Group
Re: clue for the clueless please
daemon@ATHENA.MIT.EDU (Brian)
Tue Jan 23 18:01:44 2001
Date: Tue, 23 Jan 2001 12:32:37 -0800 (PST)
From: Brian <bri@sonicboom.org>
To: "Ryan O'Connell" <ryan@complicity.co.uk>
Cc: Peter Galbavy <peter.galbavy@knowledge.com>, nanog@merit.edu
In-Reply-To: <20010123153653.A17590@look-to-windward.complicity.co.uk>
Message-ID: <Pine.BSF.4.21.0101231231350.5463-100000@cx175057-a.ocnsd1.sdca.home.com>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
Errors-To: owner-nanog-outgoing@merit.edu
Re the dialup mtu, 1500 is indeed the norm for ppp. I have a couple old
school slip friends, whose mtu is lower. They are confused.
Bri
On Tue, 23 Jan 2001, Ryan O'Connell wrote:
>
> On Tue, Jan 23, 2001 at 01:59:41PM -0000, Peter Galbavy wrote:
> > Yes, we intentionally (for some other reason during testing) set the MTU on
> > the p2p link to 554 - oops. Will get it switched back... Still wondering
> > though - if a normal dial-up has a lower than 1500 MTU, why would they work.
>
> Sounds almost certainly like an MTU problem. Try www.bt.com, if that fails
> then it's pretty much definite. Microsoft are a bit silly for setting the
> DF bit on outbound packets, firewalls at web hosting facilities that block
> all ICMP are even more silly. Why on earth Microsoft, who must know about this
> problem, block ICMP on their kit I don't know...
>
> Most if not all dialup has an MTU of 1500.
>
> --
> Ryan O'Connell - <ryan@complicity.co.uk> - http://www.complicity.co.uk
>
> I'm not losing my mind, no I'm not changing my lines,
> I'm just learning new things with the passage of time
>
