Hi, friend!
You can use the following debugging information to obtain interactive packets or use the packet capture software to capture packets.
Obtain the packet header or run the debugging l2tp all command to collect packet information during L2TP tunnel establishment and session establishment.
<Huawei> terminal monitor
<Huawei> terminal debugging
<Huawei> debugging l2tp all
Run the debugging ppp all command to collect PPP negotiation information.
<Huawei> terminal monitor
<Huawei> terminal debugging
<Huawei> debugging ppp all