Virtual IP Alias
This is the situation:
I have 5 external static ip addresses.
I set up a vitual ip (ip alias) for one of them, and I'm port forwarding port 21 to an internal server.
Great, all works.
But, it won't work on one of my ip addresses. I can change the virtual ip address, (the NAT and the rule automatically change, very cool). It works on all but one of my ip's.
Anyone have any tips on how to troubleshoot this? Where to look?
Usually that's because either something else is using that IP address, or it's not really usable in that subnet (e.g. it's a null route or broadcast address)
Can you show what IP addresses you are using and the subnet mask? You can block out the first three portions, the last IP part is what is significant here.