I have a small wireless isp. I have been trying to connect a catalyst 2950 switch to a cisco 1841 router which is connected to a t1 line. It is a managed router from my t1 provider. The 1841 has a static ip of 12.xxx.xxx.129 255.255.255.128 and a lan range of 12.xxx.xxx.128 -255. I can't change any of this. What I am trying to do is connect the 2950 to the 1841 and then connect 4 access points to the 2950. the access points are outside on a 140 ft. tower. I am using 192.168.0.20 ,21 ,22 ,23 255.255.255.0 for the ip range for the access points. The customer equipment is in the 192.168.0.30 -255 255.255.255.0 range. I only have 20 customers so far. I have not been able to configure the 2950 to receive internet from the 1841. What I have done is connect a $49 belkin home router between the two. Cable from fe0/0 on the 1841 goes to the wan port on the belkin, and cable from any switch port on belkin going to any port on 2150. Internet will work then, but during times of heavy traffic the belkin will bog down. I have read all I can on Cisco vlan and intervlan routing, trunk ports, etc., but I'm missing something somewhere. I don't need anything really complicated, just getting internet to 2950. If someone could send me a configuration as how to do this, I would really appreciate it. Thanks, Ed (System Administrator and only unpaid employee at Rural Wireless)
The reason you are not able to get internet on 2950 is because you are using private address space for your customers and you do not have any device that performs NAT operations on your outgoing traffic. What you need is a router (or if you can gain access to your ISP router, that is fine too as the 2950 cannot perform NAT operations) so that you can convert the private address (192.168.x.x range) to one of the public IP's when you go to internet. The belkin device performs exactly the same operation for you. As long as you can get a router (even a 800 series router would work), you can get it going. The other option is for you to talk to your ISP and have them configure NAT for your internal subnets.
Hope this helps.