Re: clearing dont-fragment bit

[Abraham van der Merwe <abz@frogfoot.net>]

Hi Maciej                                        >@2003.10.09_16:03:26_+0200

> > Are there any iptables extensions out there that allow you to clear the DF
> > (Dont Fragment) bit in ip headers?
> AFAIK no. Why would you want to do that?
> I think I might write a module that would do that.

I need it for tunnels. In a perfect world that wouldn't be necessary at all,
but reality is that there's many brain dead admins that filter icmp, so if
you build a tunnel over the big bad internet, you're screwed.

You can use the TCPMSS target which solves it for tcp, but you still have
the same problem with udp packets, so imho the only way to solve this
properly is to fragment packets even if DF=1.


-- 

Regards
 Abraham

Ask not for whom the telephone bell tolls...
if thou art in the bathtub, it tolls for thee.

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