Reply To: airport problem
The 10..0.1 numbers are the devices that are on your LAN. There are several network address blocks that are for local use — not able to be connected to directly over the internet. That is one of those blocks. Another commonly used one is the 192.168.. block. Probably you can access your Spectrum cable modem by logging into 192.168.100.1.
In your case, each device you have on your LAN will have an IP address assigned to it. You mentioned 3 devices (plus the AirPort) — possibly the 5th device might be something like a printer or something of that nature.
Probably your AirPort router has the IP address of 10.0.0.1 assigned to it, and it will hand out, thru DHCP, IP addresses in the 10 block to your various local devices as they come on line. You should be able to see what IP address most devices have drawn. On my Android-based phone if under settings, if I pick ABOUT PHONE and then STATUS, you can find that.