To check the packets related with CHAP, we use ... command

Hi,

You can use display command on the desired interface to check the LCP "CHAP":

[~DeviceA] display interface Lmpif 0/1/0
Lmpif0/1/0 current state : UP (ifindex: 15)
Line protocol current state : UP
Description: HUAWEI, Quidway Series, Lmpif0/1/0 Interface
Route Port,The Maximum Transmit Unit is 1500
Internet Address is 10.110.0.1/24
Link layer protocol is PPP
LCP opened, IPCP opened
Current BW: 100 Mbits
Statistics last cleared:never
   Last 300 seconds input rate 0 bits/sec, 0 packets/sec
   Last 300 seconds output rate 0 bits/sec, 0 packets/sec
   Input:  0 packets, 0 bytes
   Input error: 0 shortpacket, 0 longpacket, 0 CRC, 0 lostpacket
   Output: 0 packets, 0 bytes
   Output error: 0 lostpackets
   Output error: 0 overrunpackets, 0 underrunpackets

For more Please review the below links:

https://support.huawei.com/enterprise/en/doc/EDOC1100058399/2eda2aa/example-for-configuring-bidirectional-chap-authentication

https://support.huawei.com/enterprise/en/doc/EDOC1100125892/eee732b8/ppp-link-establishment-process

I hope it helps