装好了VPN，登录失败

[12127044]

Environment

Please complete the following information:

• CentOS7.6
• 0.3.3-4
• 1.3.15
• wired

Bug description

when I use 'ip addr', ppp0 is not always appeared, and the state is unknown, sometimes it shows ppp1, ppp2, etc.
And when I connect vpn, it failed, as the code as follows.

Output

[root@localhost ~]# zjunet vpn -c
[INFO] Try to start xl2tpd if not
[INFO] xl2tpd ready.
[INFO] try disconnecting zju-l2tp-121xxxxx@a
[INFO] xl2tpd-control done
local IP address 210.32.xxx.xxx
remote IP address 10.0.2.72
[INFO] Setting up ip route.
default via 10.15.44.1 dev eno1
default via 10.15.44.1 dev eno1 proto static metric 100
default via 10.14.45.1 dev enp0s20f0u1u6 proto static metric 101
10.14.45.0/24 dev enp0s20f0u1u6 proto kernel scope link src 10.14.xxx.xxx metric 100
10.15.44.0/24 dev eno1 proto kernel scope link src 10.15.xxx.xxx metric 100
192.168.122.0/24 dev virbr0 proto kernel scope link src 192.168.122.1
[INFO] Stopping xl2tpd
[INFO] Starting xl2tpd
[INFO] xl2tpd ready.
[INFO] Login using 121xxxxx@a
[INFO] Connection terminated.
[INFO] Retrying now.
[INFO] try disconnecting zju-l2tp-121xxxxx@a
[INFO] xl2tpd-control done
[INFO] try connecting zju-l2tp-121xxxxx@a
[INFO] xl2tpd-control done
[INFO] again