The MSR3610-X1 device cannot communicate with the CS device over frame relay

NULL

The MSR3610-X1 device cannot communicate with the CS 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

#

interface Serial1/1

 description yinlian

 link-protocol fr

 fr lmi type ansi

 fr map ip 144.xx.xxx.9 101

 #

 fr dlci 101

  broadcast

 ip address 144.xx.xxx.10 255.255.255.252

#

return

Unable to Ping the address of the peer device

[tc_wt-Serial1/1]ping 144.xx.xxx.9

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.

Serial1/1

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

……

Interface: DTE

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

Input:

  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

Output:

  3 packets, 42 bytes

  0 errors, 0 underruns, 0 collisions

  0 deferred

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.