setup L2TP IPSEC VPN in archlinux using NetworkManager

nm_l2tp_ipsec_vpn.md

setup L2TP IPsec VPN in archlinux using NetworkManager

install networkmanager-l2tp first:

yaourt -S networkmanager-l2tp

then reboot or systemctl restart NetworkManager

using commandline only

because nmtui can not create VPN connections, so I ended up creating one in the GUI and analysis generated config file

this can be done only via root, create the vpn config /etc/NetworkManager/system-connections/{vpn_name} manually:

[connection]
id={vpn_name}
uuid=aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa 
type=vpn
autoconnect=false
permissions=

[vpn]
gateway={ip_of_vpn_server}
ipsec-psk={PSK}
password-flags=2
user={given_user}
service-type=org.freedesktop.NetworkManager.l2tp

[ipv4]
dns-search=
method=auto

[ipv6]
addr-gen-mode=stable-privacy
dns-search=
method=auto

fill {vpn_name} {ip_of_vpn_server}, {PSK}, {given_user}, change uuid if needed (list current connections via nmcli c) and make sure the config permission is 600 with owner root:root, then:

systemctl restart NetworkManager # reload to detect the config
nmcli c up {vpn_name} --ask # establish the vpn connection, it will ask for password
nmcli # check connection status
nmcli c down {vpn_name} # close the vpn connection

via GNOME/KDE Plasma GUI

GNOME

KDE PLASMA

• Gateway is the ip of the vpn server
• User name is the given user
• Password can be left blank to enter when connecting
• click IPsec Settings... button
  • Check Enable IPsec tunnel to L2TP host
  • paste PSK to Pre-shared key
  • IMPORTANT Uncheck Enable IPsec tunnel to L2TP host before click OK button, I think this is a bug
• click Add button and enable