Cisco – Why does the Cisco RV180 not let me use a 255.255.254.0 subnet mask with a 192.168.2.1 LAN IP address

This can't be that hard -- but I'm thinking I'm pretty lame. Any advice?

I hate to suggest something non-cisco, but you are running older end of life'd Cisco routers -- so I will. When my PIX 506e burned up, I replaced it with a tinsy system from LogicSupply running Vyatta and have been nothing but impressed.

I just shipped out a production VMWare machine running 6 static IP's, 3 internal networks (10.0.1.0/24, 10.0.2.0/24, 10.0.3.0/24), all natting out of one IP, and all 6 external IP's randomly port forwarding inward with no respect for any one to one mappings.

If you had a spare machine you could replace the 2600 with, or purchase something solid state from LogicSupply -- you would be extremely impressed with Vyatta .. and want to shoot yourself in the foot for using the 2600 for anything but a doorstop.

password 7 0519091A3549430C

It goes without saying -- but you've posted your private IP's, router, router config, and hashed password online. Your going to change that password right?

Is anyone patient enough to list the possible subnet masks and how many users would be able to connect for each one?

Google found this, nifty subnet calculator

A small subnet will limit the number of concurrent users - people trying to hijack addresses may cause problems with duplicate IP addresses. It comes down to how hard you want to limit usage, and how hard people will work to overcome the measures you implement.

Quality of service will go a long ways to helping share the available bandwidth. Google found this link that will give you an idea on whats available.

With wireless it's easy enough to spoof/change mac addresses but you could come up with some scripts to monitor active mac addresses and limit them with iptables and some restrictive qos classes.

Edit To answer the updated question: "if I simply assign one of the netmasks above to the router, will it restrict the number of possible users effectively, as listed above? Might it screw something else up?"

Two things to watch when you do this:

• Account for the IP addresses of the Access Point and Internet Gateway (if the gateway is a different box) when deciding how many hosts to allow.
• Make sure that the DHCP service will assign addresses with the correct starting address (eg, if your network starts at zero and only has room for 12 hosts, then have the dhcp service start assigning addresses within the range). I would expect the access point to do this automagically but it's something to check.