When an NE20E-S16 is interconnected to a third-party device through MP-group, an E1 interface is physical Up but experiences protocol Down.
[huawei]disp interf Serial0/2/0:0
Serial0/2/0:0 current state : UP (ifindex: 61)
Line protocol current state : DOWN
Route Port,The Maximum Transmit Unit is 1500, Hold timer is 10(sec)
Derived from E1 0/2/0, Unframed mode, baudrate is 2048000 bps
Internet protocol processing : disabled
Link layer protocol is PPP
1. Check that parameters, such as the CRC and framed mode, on both ends are consistent.
2. Establish a link loop and perform a test. The test result shows that devices on both ends can detect the loop and the link functions properly.
3. Check that the interfaces added by MP-group are also correct. It is suspected that PPP negotiation does not work properly. Run the debugging ppp all command. The command output includes the following error information:
Aug 29 2018 17:04:17.592 huawei %%01PPP/6/PPP_Debug(d):VS=Admin-VS-CID=0x807c04d2;PPP Dbg: PPP Error:
IfIndex<61>, Protocol<LCP>, FsmState<acksend>, ErrInfo:<[Mp] LcpUpCheck, Failed because The discri Not Same.>//The negotiation fails because the received identifier is inconsistent with that of the member interface.
Run the following command and check that the identifier of Serial 0/2/0:0 is 6296429530947087967:
[~huawei-diagnose] disp inner-data ppp cid 807C04D2 info-type pppnegoinfo 61 lcp his
VmePpp App Cid: 0x807c04d2
PPP LCP NegoInfo:
4. Check that the identifier sent by the third-party device is incorrect.
The identifier sent by the third-party device is incorrect.
1. Run the shutdown and then the undo shutdown commands on the two member interfaces of the MG-group interface to trigger re-negotiation.
2. Disable the terminal identifier negotiation function on devices at both ends. The configuration also takes effect after the shutdown and undo shutdown commands are run.
To disable identifier negotiation for NE devices, run the following commands:
[~HUAWEI] interface mp-group 1/0/1
[~HUAWEI-Mp-group1/0/1] undo discriminator
If the undo discriminator command is run on the MP-group interface, the shutdown command and then the undo shutdown command must be run on the sub-channels of the MP-group to make the preceding configuration take effect.