1. Is it a P2P network? 2. What about the line of sight? (The path between two APs). For such a long range of connection(9.3KM more or less)there would be many obstacles such as trees,buildings or...

Still confused about why you want to do this. Can you draw a picture of your WiFi environment? How many CPE210 APs do you plan to use? three or two?

Can you list your network topology and AP config settings? Including the channels, power, distances, and security mode. Besides, 1. Make sure 802.11b mode is disabled.(Security) 2. Interference from...

Can you give more information about your Wi-Fi network? Including product Model, network topology, wireless environment.

Probably extreme whether (such as thunder storm) damage?

R1D2 wrote If you want to use the Linksys router as an AP, connect the client CPE's Ethernet port with one of the Linksys' LAN port, not the WAN (Internet) port. In this case, disable the DHCP server...