Problems and solutions that may be encountered during the dialing of a wireless router

　　In the process of dialing with the wireless router will always encounter this problem, perhaps you do not know how to solve, here for everyone to list the possible problems and solutions!

　　[problem] when the user uses the Quidway router connection, the wide-area network PPP protocol does not pass, and the problem is judged.

　　[resolution]: PPP agreement is ISO Two layer protocol, so the problem is to judge from the first level, with show in S N (n for the used serial port) to see if the underlying DTR,DSR,RTS,CTS,DCD signal is up, if not, Indicates that the physical line between DTE and DCE is not connected well, check the connection cable problem, when the serial port prompts up and no wrong frame, the physical layer is normal. If the physical layer is no problem, then use show in S n command to check whether LCP,IPCP open such as LCP Open and IPCP INITIAL, the PPP verification failed, check the problem of PPP verification.

　　[Analysis]: PPP protocol is not generally focused on the physical layer has problems or validation errors, the state of the physical layer can be obtained from the query information in the show in S n command, the serial port should be up when the physical layer is normal, and whether there are many wrong frames, if many of the wrong frames also indicate that there is a problem with the physical layer, Although the serial port hint is up. If the problem with the physical layer is not clear, you need to check that the validation is correct, for example Pap.

Authentication Side configuration:

config# User 169 Password 0 169

config-if-serial0# PPP Authentication pap

Authenticated Party configuration:

config-if-serial0# PPP PAP send-username 169 Password 169

Note that the user name and password are consistent in the validation.

　　[Problem] the Huawei 2501 router and CISCO router PPP docking

　　[Analysis]: Cisco router's default protocol is HDLC, and Huawei's router default protocol is PPP, when users use the Huawei router, because it is similar to Cisco's router, easily mistaken for Cisco is also PPP protocol without changing Cisco's configuration, When the command is on 2501 with show in S N (n is a string number, 0 or 1), a serial up, link protocol down is found. Change the Cisco-side protocol to PPP.

　　

　　[issue] 2509 of dial-up users dial the router from the asynchronous port (asy port) to ping 2509 of the asynchronous port and the Ethernet port on the terminal, but ping the server on the 2509 connected Ethernet.

　　[Resolve]: In the network settings on the server, point the gateway in the TCP/IP properties of the network card to the Ethernet port of the 2509 router.

　　[Analysis]: Ethernet server does not have a gateway, when the message sent from the router to the server, the server from the message to determine the source address is not the address of the network, according to the agreement that the answer message should be sent to the gateway, but because the gateway address did not set the server can not respond to Therefore, the remote terminal does not receive a message to cause a timeout error. Add a gateway after the server can successfully postback reply message to complete the process of ping.

　　[problem] two 2501 Private line connectivity, ping each other when the end of the reported serious

　　[resolution]: can be connected at both ends of the connection line to flip the clock on the serial port, configuration command for invert Transmit-clock

　　[Analysis]: The loss of the newspaper may be on the line of the clock dislocation caused by the routers at both ends of the router can not be synchronized, in the interface of the clock flip invert transmit-clock equivalent to make the clock change half a cycle and make the clock alignment. The clock is not allowed to lose the only reason for serious, if the clock changes can not solve the problem, and verify that the configuration is correct, you need to check the line is normal.

　　[problem] when configuring X.25 address mappings, prompt address mappings are repeated.

　　[Resolve]: Use the command no x25 map IP to remove the previous address mappings, and then reconfigure the new address mappings.

　　[Analysis]: In an X.25 address map, an IP address can only correspond to one x121 address, which causes a conflict when an IP address is configured to two different x121 addresses.