Re: internal host can not access hotmail

[Yuwen Dai <yuwend@gmail.com>]

On Tue, 22 Feb 2005 10:55:27 +0800, Wenzhuo Zhang <wenzhuo@zhmail.com> wrote:
> Yuwen Dai wrote:
> > Any advice to diagnose this problem?  I once thought maybe something
> > wrong with the FORWARD rules, and tried to log the blocked
> > packages. But there's no log info.
> 
> Probably you're encoutering the Path MTU Discovery problem. There are
> serveral solutions to this problem.
> 
> 1. Lower the MTU of the network interface of your internal host.
> 
> 2. Use the clamp-mss-to-pmtu feature of iptables:
>     # iptables -I FORWARD -p tcp --tcp-flags SYN,RST SYN -j TCPMSS \
>          --clamp-mss-to-pmtu

Thank you.  I used this rule to solved the problem.



> 
> 3. Use the clamp MSS feature of rp-pppoe (e.g. -m 1412).
> 

Now ppp uses a rp-pppoe.so plugin in peers/dsl-provider:
plugin rp-pppoe.so eth0

instead of
pty "/usr/sbin/pppoe -I eth0 -T 80 -m 1452"

So I don't know if I can use an option.

Best regards,
Dai Yuwen