Comcast cable static IP / NAT / SMC modem / configuration basic questions
Posted on 2008-11-07
working with a comcast smc modem, I have some questions. The modem they supplied has 4 'lan' ports on it. Our network (firewall to a dual nic sbs box to the rest of our network) was plugged into port 1, 2 other networks were in port 2 & 3. our firewall and the other networks were getting 10.1.10.x addresses from the smc (NAT), and we shared a single public IP.
Now we have a block of 5 static IPs. comcast says the gateway is .18 and our block of IPs is .13 - .17. We want our network to have it's own IP. I entered the .13 info into our firewall and it gets out fine. And using that IP, we can get in also with RWW.
Comcast wasn't much help in helping me understand....
so the other static IPs aren't being used right now, right?
those other networks will still keep getting nat addresses and a public ip of .18, right?
the key question: the SMC box is set for NAT, but yet we are connecting to it with a public IP on the LAN side. That's OK? It passes all traffic for .13 right to our firewall? No rules are needed? But anything else comes into .18 and you need rules to route inbound? (The smc is both NATting and simply routing?! Neat!