2 LANs, 2 servers, 2 IPS, one ADSL

[bradc]

I've got one ADSL connection (one modem), and 2 static IPs. I'd like to connect two LANs to the modem, each using one of the IPs. Each of the LANs will have one net accessible server and other local computers/printers.

At first glance I would create two LANs, each with a router and a server attached to the DMZ of that router. Then connect the two routers and the ADSL modem with a switch. If that's right, how do I access printers between LANs? Or computers between LANs? Get'n a bit over my head...

fyi, mixed PCs and Macs.

tia, Brad

 

[gurner]

are you refering to 2 machines and 2 IP addresses or 2 multiple workstation networks.

you refer to 2 net accessable servers (these could have the fixed IPs, and act as default gateways to workstations) how are you planning to assign IP addresses to the workstations (all fixed internal IPs or DHCP assignment)

what Subnet are you planning to use (255.255.255.0 or 255.255.0.0)

Would it be possible for simplicities sake to assign both LANs the same subnet (e.g. all internal IPs like 100.10.x.x or 100.10.1.x example) why 2 LANs? why not 1 big LAN.

It is possible if you over complicate things and both LAN are on different subnets then IP forwarding would enable communication between LANs, but i think it would be preferable if it could be kept simple.

I think you are going to need to read a good book on Networking or TCP/IP addressing (Sybex are quite good)

or try this

http://www.networkmagazine.com/article/NMG20000724S0035

 

[bradc]

Thx for the response Girth,
Maybe I am overcomplicating it. I was thinking of two distinct networks because they are for different uses. The first is a net server, database server and backup/monitoring server. The second is a development net server (accessed by only a few people), desktop systems and printers.

I would like the backup server to be able to access the dev network and it's printers though.

Internal IPs could be fixed or dynamic. I guess I was thinking of using two routers because the cheapo ones that I've used will only expose one server to the net.

Thx for the link, I'll do some more reading. If I can set it up as one network it would certainly simplify things. Simple is good.

One question. If I have two routers that are using the same subnet but different IPs, will this behave as one big network? That would do it for me if it works.

Brad

 

[gurner]

You only really need 1 router a couple of hubs, lots of Cat5 and if IPs are static, a good Subnet Calculator (or your brain working overtime)

http://www.howstuffworks.com/router1.htm

try this one as well

 

[gurner]

An somesort of Firewall between the Router and the Internet
either a dedicated Firewall box or a simple 486 tinpot configured to do nothing but filter through the 'wall.
(these are ten a penny these days)

 

[bradc]

Okay, but if there is only one router, won't it be using a single IP? Then, everything behind it (both servers), appears to be from that IP. I would only be able to use one server at a time, right? maybe I just need a better router that can handle 2 IPs?

 

[gurner]

1 ADSL line and 1 Router is quite fast enough for a Network of about 1-30 machines all at the same time. depending on how good the bandwidth on your network is! This is up to how well you build your network and what components you use and how efficiant things like packet filtering across the router is.

I believe that a decent router can have a multitude of IP addresses, I don’t think any of your servers need the 2 fixed IP addresses you speak of (they do need fixed IP addresses but not publically visable IPs, only internal IPs like 100.0.x.x or something so that workstations also on 100.0.x.x can see them)

The only time a server would need a fixed public IP address is if it was an IIS server for example or if a small network with 1 server wanted Internet access and they wanted to use Internet Connection Sharing to enable everyone to browse the web.

And again a Firewall to filter access is vital with ADSL lines amoungst other connections.

Again I think simplicity is the key.

 

[bradc]

Both servers do need fixed public IPs because they need to be net accessible (ie, to a public viewer's browser). One is a primary server and one would have intermittent access granted for off-site development members.

If I can configure a router to show one server to the public as one IP and one as the other IP (though they both actually have local IPs), it would work. The rest of the computers would be behind the router and firewall. We have this working on a single-server with everything behind a router/firewall now. Just need to add whatever is needed to support the second server.

 

[gurner]

ah! excuse my forgetfulness i didn't realize you were going to actually host

Internet Internet
| |
Firewall Firewall
| |
Server1 | Server2 Hub-Router-Hub
\ | / /|\ /| \|/ Server1+2 rest of LAN
Router
/|\ (server1 is Web/bkup/db)
Wkstns+more servers (server2 is dev)
Printers

How about Server1+2 with the fixed IPs, again to keep it easy on your brain one of the other servers could be the PDC, dynamically assigning IPs (coz if yur gonna have to worry about web servers you dont want IP address grief as well)

Which machine will handle the ADSL line (via the Firewall and router)? up to you.

How many NICs will you have Bound to the fixed public IP address servers? (1+2)(2 i hope, one for the public IP and one for the internal IP, to aid LAN users)

 

[bradc]

Wow, what a day,,, I'm back.
Thanks for the help Girth. Nice pics! This gives me enough to chew on. I hadn't thought of doubling up the NICs. That makes a difference.
Brad