Zentyal as a gateway: urgent help needed [SOLVED]

[posix]

Hi everybody,
I am currently trying to set up Ubuntu server (10.04.2) with Zentyal 2.0 (latest packages from ppa) as a gateway, and I ran into problems.

First of all, I recognized that ipv4 packet forwarding is not enabled in sysctl.conf. Should I enable it manually, or I missed something in Zentual configuration?

Second, I've added default gateway (the gateway ip of my isp) to the external iface configuration, but it doesn't work. I investigated the problem and I see that gateway address is in the /etc/network/interfaces, but it it missed it routing tables. If i manually restart networking (/etc/init.d/networking restart) it works until I reboot my machine.

Currently I'm reinstalling Ubuntu to start configuration from scratch, but I really sure that this won't help and I was doing something wrong.

Please help.

[robb]

I would advice to use the Zentyal installation image when (re)installing Zentyal. If that is not possible (for instance when using a VPS with limited dirstibutions available) you're stuck with using Ubuntu and add the Zentyal packages afterwards.

Can you post a complete config so we can see what is going wrong?

[Josep]

After installing Zentyal, you need to go into the Network module and configure your interfaces there, so that changes stick.
If you are applying changes directly into the configuration files they will be lost or conflict with Zentyal.

[posix]

Sorry for disappearing, I have some problems with my installation cd (bad day!) but it soved now.

I reinstalled Ubuntu completely and reconfigured interfaces. It seems that now my external interface doesn't forget gateway every time I reboot the system, but now I can't make Zentyal NAT to work.

What steps should I make exactly to enable NAT? I configured external interface, marked it as "external", configured one of the internal interfaces, enabled DHCP for it using Zentyal interface as gateway for this internal subnetwork. DHCP works fine, routing shows that internal Zentyal address is used as gateway, but no hosts behind Zentyal can be reached.

2 Josep: I use Zentyal web interface to configure it. But every time I saved changes for network module, ISP gateway ip was dropped (still present in web interface, but not in route tables). Manual network restart from console was fixing that problem until next reboot/web interface save. Anyway, it seems that reinstalling Ubuntu and Zentyal fixed this strange bug. Now for some reason I can't make NAT to work.

[posix]

Fixed my problems somehow by reconfiguring all modules from scratch.

Thanks for all who helped!