NAT on linksys wireless router

[linux00]

I have a linksys wireless router and four pcs, two connected
via wireless and two other wired. I have a block of static ips and I have a security cameras over ethernet. I would like to know how to configure NAT so I can point my private LAN addresses to the Public IPs. Thanks

 

[franklin97355]

How many public IPs do you have? Usually a router takes one public IP (WAN) and routes it to the private network (192.168.x.x)

The answer is "42"

 

[linux00]

I have a block of five public IPs. So the router is the one
that takes the public IP under the WAN tab???? I thought you
had to do port mapping on each individual machine to the public IP :s

 

[smah]

I think that you'll find a problem with where you're trying to go, but let's get there one step at a time. The basic Linksys router will provide Network Address Translation (NAT) for one public IP to all the clients (up to 255) in the private network behind it.

Port forwading (mapping) will allow you to forward communication for a particular port from the 1 public IP address to 1 private IP address on the LAN side.

Here's where you might run into a little problem. I assume that your security cameras are standalone systems that each get their own [different] private IP address. So, the important part of this conversation will be about the capabilites & fuctions of these cameras and what services (ports) that you want to forward through the router.

 

[linux00]

Ok, and lets say I just want to point the public addresses to
the private adresses of my pcs. Would I just port forward each private address to one public IP????

 

[smah]

The port forwarding functions are based on ports. Don't confuse 'ports' with IP addresses. The basic linksys router will work with 1 public IP address. You could forward dozens of different ports of that public IP address to dozens of different private IP addresses or all ports to 1 private IP address. The rules for the 1 public address are based on the ports.

For example, TCP port 80 is the standard listening port for a web server, port 21 is the standard listening port for an ftp server. So, for incoming connections on the 1 public IP address, you could forward port 80 to internal machine "A" by it's private IP address and also forward port 21 to internal machine "B" by it's private IP address.

Now, back to the cameras (and whatever else you want accessible from the internet)--- Do the cameras each have an embedded web server listening on port 80, without the need of another computer to connect to? Or, do they all connect to 1 computer? Or do they each connect to a different computer?

So, to answer

I just want to point the public addresses to the private adresses of my pcs.

Each basic router can only work with 1 public IP address. To effectively use the router that you have for 5 different external services, you would want those 5 services to use different ports on 1 public IP address. If you really must use 5 public IP addresses, you'll some different hardware than the 1 router that you currently have. This is where I've been heading and the possible 'problem' that I mentioned earlier in this conversation. However the real answer, depends on the features/capablities of the services & devices that you're trying to get through the router.

 

[linux00]

Well, basically the thing that I care the most is getting in to the 4 machines remotely using that public IP. so, let me see if I understand, those four computers have private IPs, I would use one public IP on the router and port foward port 3349 for remote desktop to one of the machines by IP. is that correct????

 

[smah]

OK that helps. Windows Remote desktop uses port 3389 by default. Since your router will only forward 3389 to one particular private IP address, you'll need to make a few changes to access the other three. RD can be set to listen on other ports besides the default. KB306759 & KB304304 will get you there. I'd suggest using 3390-3392 for the other 3 machines. You will connect to all of them using the one same public IP address, just different ports. You'd set the router's port forwarding for each port to a different internal IP address.

 

[linux00]

Ok, thank you very much you were of great help...