Dynamic - static WAN IP and router setup help

[nell1]

Hi all, hope someone can give me a few pointers.

Had dynamic ip ADSL service form BT. We want to install a mail server so have upgraded to staic IP. Now we have upgraded BT have given us multiple ip's, consisting of a "network ip", "router ip" and 5 "user ip's".

What I wanted to do was to really have 1 ip that I could send all mail to, then port forward on the router to an ip on my LAN that is the mail server. I cannot get access to the router that BT have supplied so I bought a Netgear RP614 cable/dsl router thinking that I could simply route from there.

Having a few issues though, bit confused by all the ip's that bt has supplied and what they are for, particulaly the 'network' and 'router' ip's.

Does what I am wanting to do sound pretty straight forward to any gurus out ther?

Confused. Any help gratefully recieved!

Nell1

 

[vikmere]

well actually its rather straight forward..Let me ask.. What is BT? Is it SBC. How many total static IP have you got? What mail server have you installed? How many computers are you going to network?.

 

[bcastner]

I would purchase an inexpensive switch. I would connect the existing ADSL modem to the switch. I would connect the mail server to the switch. And I would connect your new router to the switch.

The mail server would use 1 of your 5 static ip's.

The router would be given 1 of your 5 static ip's, have DHCP enabled for your local LAN unless you have a local DHCP server.

You would not need to forward in this instance for the mail server, but a firewall is recommended. It will have full and unmitigated access to the internet.

Your router would use the second static IP to do NAT servicing of the rest of the network. To access you mail server you would use its public IP address, the first static IP.

I would not use BT to route my LAN traffic as they are suggesting. All you were missing is a switch to permit the mail server completely clean access to the internet without compromising the security of your local LAN.

You can ignore all the other IPs BT gave you.

 

[nell1]

THanks for the replies vikmere & bcastner. I'll reply to vikmere first. BT is a telecoms provider in UK, they provide our ADSL connection, they have supplied us with a router, however they do not allow us access to it. Total static IP's are as follows, 1 network ip, 1 router ip and 5 user ip's (as BT have described it). Not sure what you mean by SBC. At the moment we have an exisiting network of about 50 computers connected via a switch. Mail server we will be using is MDaemon Mail Server.

bcastner,

It is the IP assignment that has thrown me a bit. As far as I understand it (and I could be and probabaly am wrong), the BT supplied router will be assigned 1 ip, not sure where the network ip comes in. Did think about having the email server as a standalone comp completely open to the net, however thought it might be better to hide it behind the LAN and just use the router to forward email requests.

The plan I had in mind was;

internet ---Bt router ---- new router---- switch -- lan

getting confused when thinking about all the ip assignments, gateways etc..

do you think i'm way off mark?

Thanks again for the replies!!

Nell1

 

[bcastner]

Yes, I was thinking if putting the mail server essentially stand-alone on its own IP for simplicity.

But there is no requirement to do so, forwarding the necessary ports works perfectly well.

What you have proposed should work fine.

Please let us hear back how your fare with this project.

 

[vikmere]

Hi Nell,
Well here is exactly what you can do. Since you have no access to the router they have provided you, you cant really use that static IP. So basically what you do is as you mentioned connect the new router behind the BT router and assign it a static IP. So the new router will have a static AND a LAN IP for eg 192.168.1.1(Linksys routers use that). Remember you will have to connect the modem to the Wan port of the BT router and the BT router to the Wan port of the local router. On the local router assign it the static WAN IP you will choose for the mail server. Now forward all requests on port 80(for web hosting), port 110(for incoming mail POP3) to the local machine which has MDaemon.(By the way have you thought about Merak mail server. Its good we are currently using that).