Had to replace ADSL modem on a network running Server 2003....

JohnCleary

Folks,
Had to replace an ADSL modem today on a small network. The modem went into a switch, and the switch was connected to PC's and a Server 2003 machine which ran DHCP, Exchange Server etc...

Problem is the old ADSL modem is fried so couldn't check previous settings.

Should the ADSL modem be set to bridge mode since Server 2003 is handling DHCP etc?

I'm having an issue now that Exchange won't send/receive any external email (internal is fine)

Thanks

Mr. Fancypants

Chances are it was in routed mode and there was a NAT rule for port 25 to the internal ip of the Server. Is there a seperate firewall or is there ISA installed on the server?

JohnCleary

mbroaders wrote: »

Chances are it was in routed mode and there was a NAT rule for port 25 to the internal ip of the Server. Is there a seperate firewall or is there ISA installed on the server?

There was a separate firewall but had to remove it as couldn't get an outside connection at all with it, they Just needed to get back online so I left it at that as was just trying to help them out

brianwalshcork

You'd only need bridge modem if something else was handling the setup of the dsl connection.

What edition of win server is running? Is it small business server? If so, check if isa or the rras service is running and if you have a ppoe connection in your network connections.

What is the server ip and what is the default gateway on the clients?

What was the firewall that you mentioned above? That may have been dialing the ISP also .... But as its out of the equation now, then it need not be considered for the moment.

I'd bet that it was either exactly as mbroaders posted .... with dhcp on the modem disabled, or bridged with the firewall handling the connection setup.

Mr. Fancypants

Yep if you got rid of the firewall you will most likely need to change it to routed mode to allow the dsl router handle the connection. Add a NAT rule to allow port 25 in to the server ip to get mail flow working. That's assuming all traffic is allowed out which is the most likely case if the router has been reset.

JohnCleary

Thanks for the responses folks.

Given that there *was* a hardware firewall installed... When I introduced the new ADSL router to the equation I couldn't ping the ADSL router from the server, so as a temp. fix I removed the hardware firewall so they could get back online.

I now suspect that the ADSL router was bridged so that it would work in harmony with the hardware firewall.

I will return tomorrow and try to bridge the ADSL router while returning the hardware firewall to the equation... it will cost nothing to try anyway!

Originally it was: Phone Line -> ZyXel Prestige 650 (ADSL router) -> Hardware firewall -> Switch: PC's & Windows 2003 Server



Given that the gateway on the Server 2003 machine was 192.168.0.254... should this be the static IP of the ADSL router? Or would the firewall have been the gateway?

JohnCleary

This morning I connected the Netopia router and set to bridge mode, but couldn't get an outside connection.

I re-conencted the firewall and at least from the server I was able to ping the gateway (so we know the firewall is the gateway)

One observation: The green 'Internet' light on the Netopia does not light up at all (not green, not red). The DSL light is green OK, but not the Internet light... is this normal?

JohnCleary

Got it sorted! The Firewall was being fussy about when the bridged router was connected. Firewall had to be up and running, then connect the bridged router... problem solved thanks folks!