I have generally managed my routers by telnet connection to their WAN IP address. They have always been accessible by WAN or LAN address to a telnet connection. Rarely I would log in via the SDM. One of my routers suddenly is inaccessible using either method, although I can gain access to it through the console serial port. I have checked and compared show runs between routers but cannot figure out what needs to eb done to re-enable Telnet. I have verified that the HTTP server function is enabled so SDM should at least be working. Any advice would be appreciated.
I have this problem too.