Topic: SME Server as gateway, with Linksys router as modem?

[piedie]

Hello everybody. (And also: {newbie-alert} and {bad english-alert}!)

I am installing SME server in a small company where the used to have a Linksys modem/router (WAG200) to give all clients internet-access. (About 6 clients). I wanted to use the SME server as gateway, so that I could access the server from outside of the network, to be able to reach the mailserver etcetera. Therefore, I wanted to use the Linksys as modem only, so I disabled almost every function (wireless, dhcp) Also, I made a DMZ for SME server.

The problem is, that I do manage to get internet to my clients, but only for lets say 45 seconds. After that, connection drops, while the modem is still connected. Then also the serverconsole fails in connecting to the internet. After reboot it works fine again, (both on server and clients) but again only for so many seconds. I now set it up as server-only mode, it works quite fine, but I am not really sure wheter i can use the mail server capability.

Does anybody have any idea what this may be? Any tips for setting up the network with my Linksys modem/router as connection to internet? Any general hints maybe?

Thank you very much.


{/newbie-alert}
{/bad english-alert}

[bpivk]

Don't set the server in server/gateway and put it in a DMZ.
Use one of the next two options:
- use server as gateway and configure your router as an access point only (it works great on my network)
- use server as server only and open the apropriate ports on your router (80,... what you use and need)

One of the problems could be a bad NIC or lack of RAM so could you also put your server's specs.

[piedie]

The server is brand new, with 1 Gb of RAM, so I'm guessing that that is not the problem. I put in two PCI NIC's, because SME wouldn't recognize the built-in NIC on the Asus motherbord. Both are the same, Realtek chipset, one of them is old however, but I don't think it is broken, it was working when I put it in, and it did work, although it was just for some seconds. More specs tomorrow when I am back there.

Question in reply to your server-only suggestion: could I still use the mailserver capabilities of the server when it is in server only mode?

Thanks!

[bpivk]

Yes the server will still function normaly but it has to be in server/gateway mode if you want to use the firewall. If you keep it in server mode make sure that you use another firewall in front of your server.

[piedie]

... which can be that Linksys, right?

Which ports would I have to open and link to SME Server?

Thank you!

[bpivk]

Well it depends on what you use...

22- SFTP
80 -HTTP
443 - HTTPS
993 - IMAPS
995 - POP3S

Theese should be enough.

Now just put your router in front of your server and put the server in server only mode. Then forward all the ports to your server.

[gippsweb]

We use a Billion instead of a Linksys and have bridged the modem and just use PPPoE to connect to the internet from the SME machine.
I find this a lot more stable than using the modem standalone.
And also stops doubling up on any port forwarding you may need to do.

[piedie]

But will a Linksys wag200g be able to do that? It is not manufactured to act as modem only....

[gippsweb]

Yes it will do it, but you will lose all it's functionality and it will just act like a dumb modem. ie, no wireless.

[piedie]

I know, but i have an AP for that. That way my server can work in gateway mode...

[hordeusr]

Maybe it's just me, but I don't see the advantage of using SME as a gateway if you already have a gateway/firewall set-up and working.  What kind of email access do you want remotely?  Port forward 443 and they can have webmail access.  Port 25 so you can receive email into the SME from the outside world.

[bpivk]

if you already have a gateway/firewall set-up and working

Well the advantage is ease of opening ports. My router doesn't even open or forward ports when i instruct him so i have demoted him to AP only duty.  

[hordeusr]

In that case I don't blame you.  That's not much of a router anyway....

[bpivk]

Well i needed a wlan router and i got Belkin which (even after firmware upgrade and contacting tech support) doesn't respond to some ports (standard server ports - 80,21...). But SME does a better job routing trafic.

[del]

Hi All,

But SME does a better job routing trafic.

I haven't found a router that does ddns properly either SME does ddns without a problem

Regards,
Del

[p-jones]

Piedie

Setting up your SME and putting it into a DMZ should work just fine. You then rely on SME as the router and firwall and life does become a bit easier.  I have done this successfully with Billion, D-Link and Dynalink Routers as it avoids the double-nat issues and has all ports on the outward facing NIC available from outside

I have also successfully used DHCP bridging (DHCP Spoofing or half-bridge) and set the outward facing NIC in SME to DHCP. This is a variant of the PPPoE mentioned above. This automatically gives the outward NIC the public IP. This method has a few more issues than above.

These experiences tend to neutralise some of the comments above. They also more fully exploit the features os SME in server - gateway mode.

The issue of whether the server and firewall should be in the same box is seperate issue

I had less success when I used a Zyxel 660 wireless and ADSL router even though the capabilities of that router were similiar. Dropping out was one of the issues.  After doing some reading, I found that disabling wireless only really turned on or off the wireless reciever/transmitter, leaving the IP routing/filtering rules the same. These rules differ from a standard router because of the additional interface (the wireless interface) which is intended to face inwards but in the case of an SME server in gateway mode, ends up between the server and the router.

I think you would do better if you were able to use a different router without the wireless interface. You might also gain some additional leads by browsing the IPCop forums. www.ipcop.org.