Subject: Re: Path MTU discovery
To: Wolfgang Rupprecht <firstname.lastname@example.org>
From: Christopher R. Bowman <crb@Glue.umd.edu>
Date: 07/15/1997 15:20:39
On 15 Jul 1997, Wolfgang Rupprecht wrote:
> email@example.com (Kevin M. Lahey) writes:
> > In private e-mail, Perry pointed out that the BSDI stack supports it,
> > and mentioned something about it being publicly available.
> > We have source for BSDI at work, so I didn't pursue the publicly
> > available part, but the code is definitely there.
> I've used BSDI 2.1 for a year now and the MTU path discovery code,
> without fail, will "discover" 1500 byte MTU, 1460 byte tcp_mss. This
> is the same answer as my SunOS machine that has been running a fixed
> 1460 byte tcp_mss for > 5 years now.
> So unless one is on a network where the MTU is larger than 1500 (FDDI,
> 100b-tx w. hacked packet size etc.) there is very little interesting
> for the MTU discovery code to discover. The answer is almost
> certainly "1500".
> Wolfgang Rupprecht <firstname.lastname@example.org> http://www.wsrcc.com/
What about slip or ppp, they don't ahve MTUs of 1500 do they?
Christopher R. Bowman
My home page