--On Wednesday, January 15, 2003 5:38 PM +0100 Zbynek Cvach
<Z.Cvach@pcs.cz> wrote:
> Hello,
>
> 1) Thanks - shorewall save me a lot of time!
> 2) I try - exactly: I must :-) - configure a VPN server behind 2 NATs.
>
> My situation:
>
> RoadWarior - INet - ISP Router (NAT+PortForwarding) - Inetranal Router
> (running Shorewal, NAT+PortForwarding) - Inetranl VPN Server
>
> If RoadWariror try to connect Internal VPN Server then connection failed
> with "GRE: Bad check chcksum from pppd" message.
>
> If I try connect to this VPN server from LAN then connection is
> estabilished well.
>
> I have rules
> DNAT net loc:10.1.4.20 tcp 1723
> DNAT net loc:10.1.4.20 gre
>
> Can be problem with "double NAT"?
> Can you help please?
I suggest that you try a Google Search for "GRE: Bad checksum" --
turns up
100''s of hits.
-Tom
--
Tom Eastep \ Shorewall - iptables made easy
AIM: teastep \ http://shorewall.sf.net
ICQ: #60745924 \ teastep@shorewall.net