H3C Technologies H3C SR8800 - Manual (Page 48)

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[Sysname-E1 3/1/10] quit
# Create MP-group 3/1/28 and assign an IP address for it.
[Sysname] interface Mp-group 3/1/28
[Sysname-Mp-group 3/1/28] ip address 10.1.1.2 24
[Sysname-Mp-group 3/1/28] quit
# Configure Serial 3/1/9:0 and Serial 3/1/10:0.
[Sysname] interface Serial3/1/9:0
[Sysname-Serial3/1/9:0] ppp mp Mp-group 3/1/28
[Sysname-Serial3/1/9:0] quit
[Sysname] interface Serial3/1/10:0
[Sysname-Serial3/1/10:0] ppp mp Mp-group 3/1/28
[Sysname-Serial3/1/10:0] quit
You can use the display interface serial 3/1/9:0 command, the display interface mp-group 3/1/28
command, and the display ppp mp command to display the connection status, and use the ping
command to check network reachability.
Troubleshooting CPOS interfaces
Interface physical status is up, link protocol status is down, and
loopback is detected
Symptom
Connect the CPOS interface of your router to that of another vendor through SDH, bundle E1 channels
on the interface to form a serial interface and encapsulate it with PPP.
Perform the display interface serial command to check information on interface status. It shows that the
physical state of the interface is UP, but the link protocol is DOWN; and loopback, though not configured,
is detected on some interfaces.
Solution
The fault occurs when the multiplex unit configurations on the SDH transmission device mismatch the E1
channel numbers on the CPOS interface on your router. This can result in timeslot inconsistency at the two
ends of transmission and also PPP negotiation failures and LCP anomalies.
In addition, if an idle timeslot on a looped serial interface on the transmission device is used in
transmission, the information that loopback is detected is displayed. Use the debugging ppp lcp error
command to check loopback information.
Follow these steps to solve the problem:
• Use the display controller cpos e1 command to view the multiplexing paths of the E1 channels or
calculate the multiplexing path as shown in “
Calculating E1/T1/E3/T3 channel sequence
numbers .”
• Check the configurations on the transmission devices against the calculating result in the last step to
make sure the same E1 multiplexing path is configured.