After configure according to normal configuration, interconnect serial port, communication failed.
ip address 188.8.131.52 255.255.255.252
what we can see from “debug ppp” information is send message, no received message.
*0.78675460 Permasteelisa PPP/7/debug2:
Serial2/0/0 LCP TO+(Timeout with counter > 0) Event
state reqsent , Retransmit = 2
*0.78675660 Permasteelisa PPP/7/debug2:
Serial2/0/0 Output LCP(c021) Pkt, Len 31
State reqsent, code ConfReq(01), id 25, len 27
MRU(1), len 4, val 05dc
MagicNumber(5), len 6, val 04b0ad5e
MRRU(11), len 4, val 05dc
Discri(13), len 9, val 0145d971d8116a
*0.78676060 Permasteelisa PPP/7/debug2:
Serial2/0/0 : send packet to fpath!
review interface informaiton：
Physical layer is synchronous,Baudrate is 64000 bps, Interface is no cable
Last 300 seconds input rate 0.00 bytes/sec, 0.00 packets/sec
Last 300 seconds output rate 3.41 bytes/sec, 0.11 packets/sec
Input: 0 packets, 0 bytes
47882 non octet_aligned, 11 abort sequence
0 giants, 59 CRC, 0 overruns, 0 carrier lost
Output:118 packets, 3658 bytes
0 underruns, 0 CTS lost errors
DCD=DOWN DTR=DOWN DSR=DOWN RTS=DOWN CTS=DOWN
received a lot of fault message, and the amount of message is increasing.
Execute command “invert receive-clock” to turn received clock frequency over, problem solved.
We can judge from information upwards that message has been received, but those message can’t reassembled into data, received data can’t be displayed with “debug”, the phenomenon caused by clock produces delay on line leads to clock of synchronized serial port difference.