Re: can not set mtu on tun0 via ppp, mssfixup not working

[Dave Edwards <davo_(_at_)_chunga_(_dot_)_apana_(_dot_)_org_(_dot_)_au>]

'To quote tias_(_at_)_tiasarea_(_dot_)_org_(_dot_)__(_dot_)_'
> Date: Wed, 4 Sep 2002 20:11:35 +0200
> To: misc_(_at_)_openbsd_(_dot_)_org
> Subject: can not set mtu on tun0 via ppp, mssfixup not working

> Hi all,
> 
> i`ve been looking into this problem for some time now and i have no clue
> on what happens ....
> symptoms:
> i run obsd 3.0 on pentium 166
> i have adsl and connect via pppoe
> i nat on my internal net
> the mtu on tun0 is set to 1500 by default
> i have in my /etc/ppp/ppp.conf in a pppoe profile:
> set mtu 1492

And there's the problem.  Try "set mtu max 1492".
I got caught with this one too for a couple of days..

> on the obsd box,
> if i ifconfig tun0 mtu 1492
> then i can access www.pt.lu with lynx (with mtu 1500 i can not)
> but on the internal net no client can access www.pt.lu
> (except via a telnet cession, which makes this problem
> so strange to me ( i get the page after a GET / HTTP/1.0))

I also had some trouble with this.  It came good after making 
the "mtu max" change in ppp.conf, but I also added "scrub in all" 
in pf.conf at about the same time and I'm not sure which one 
actually fixed ti :-)

ciao
dave
-- 
Dave Edwards  	           
davo_(_at_)_chunga_(_dot_)_apana_(_dot_)_org_(_dot_)_au || davo_(_at_)_sa_(_dot_)_apana_(_dot_)_org_(_dot_)_au
Adelaide, South Australia                  
----