I'm searching for a G1100 router on Ebay so that I don't have pay Verizon $199 for a new one. [FYI: I prefer to connect through coax so the router has to be a G1100] However, whenever I find a reasonably priced router it seems to be either a Frontier model or one loaded with Frontier firmware. Are these Frontier routers compatible with Verizon Fios?
No they are not. People will try and tell you that they were originally Verizon Fios routers so when Frontier took the customers over in certain regions they flashed a new firmware to operate on their services. Look only for a Quantum Gateway G1100 branded only to Fios.
also be careful since some sellers are selling stolen Verizon Fios routers so even if they are branded to Verizon the attempt will trigger a lost or stolen router alert and you will not be able to use it, and lose your money.