The MSR3610-X1 device cannot communicate with the Cisco device over frame relay. When checking the connectivity, the physical layer of serial port and the protocol layer were up, but the two devices could not communicate with each other.
1. First, check the interface state. The physical layer and protocol layer states of Serial1/1 port are up
[route-Serial1/1]dis ip int br
*down: administratively down
(s): spoofing (l): loopback
Interface Physical Protocol IP Address Description
GE0/0 up up 198.xxx.xx.31 --
GE0/1 *down down 9.xx.xxx.210 --
GE0/2 down down -- --
Ser1/0 down down -- --
Ser1/1 up up 144.xx.xxx.10 --
2、Secondly, check the interface configuration and the configuration is correct:
[route-Serial1/1]dis cur int se 1/1
fr lmi type ansi
fr map ip 144.xx.xxx.9 101
fr dlci 101
ip address 144.xx.xxx.10 255.255.255.252
Unable to Ping the address of the peer device
Ping 144.xx.xxx.9 ( 144.xx.xxx.9 ): 56 data bytes, press CTRL_C to break
Request time out
Request time out
3、For the problem that the frame relay Link-layer protocol is up but cannot ping each other, we should confirm whether the address mapping configuration of the devices on both ends is correct or whether the route is reachable.
The device configuration is normal and the routing is normal, so these two issues are excluded.
4、Check the interface information and find a large number of error packets and increase in the input direction of interface.
Current state: UP
Line protocol state: UP
Link layer protocol is FR IETF
LMI DLCI is 0, LMI type is ANSI, frame relay DTE
LMI status enquiry sent 3, LMI status received 3
LMI status timeout 0, LMI message discarded 0
Physical layer: synchronous, Virtual baudrate: 64000 bps
Cable type: V35
Clock mode: DTECLK1
Last 300 seconds input rate: 0.00 bytes/sec, 0 bits/sec, 0.00 packets/sec
Last 300 seconds output rate: 0.00 bytes/sec, 0 bits/sec, 0.00 packets/sec
3 packets, 52 bytes
0 broadcasts, 0 multicasts
5270 errors, 0 runts, 0 giants
0 CRC, 0 align errors, 0 overruns
5270 aborts, 0 no buffers, 0 frame errors
3 packets, 42 bytes
0 errors, 0 underruns, 0 collisions
In general, if there are many error packets in the input direction, it may be due to a clock problem.
Invert receive-clock: To eliminate the delay of half clock cycle on the circuit, invert the received clock signal of the serial port synchronously on the DTE side.
After this command is configured on all interfaces, it can be up normally and ping each other with the opposite end.
The problem is resolved after configuration invert receive-clock under the interface.