If it is configured as auto obtain IP, the client can dial up and obtain address to access internal network. If designated address pool of virtual template is deleted, dial-up fails and it is timeout after the client manually configures IP address.
DEBUG PPP packet:
PPP I IPCP(8021) Pkt, Len 42
State reqsent, code ConfReq(01), id 6, len 10
IP Address(3), len 6, val 00000000
Login on the device and check the configuration and there is no problem. Users can dial up with auto obtain IP, it indicates that the configuration and network environment are not problematic.
Recover it as manually designate IP mode. DEBUG L2TP and the establishment of TUNNEL is normal. DEBUG PPP and it is found that PPP request is rejected.
Check configured IP address with user. The user configures IP address on actual network connection. Urge the user to configure IP address on dial-up connection. Dial again and it can pass.
If PC correctly configures IP address, normal IP address can be seen in PPP packet.
DEBUG information and it is IP Address (3), len 6, val 00000000
It indicates that PC sends PPP packet without IP address. It need require IP allocation.
Normal information should be IP Address (3), len 6, val 0a0a0a02
IP address of PC is 10.10.10.2