l2tp/ipsec problem

Solution 1:

The two most likely issues users have with network-manager-l2tp :

1. Using a VPN server that is using legacy IPsec IKEv1 ciphers that current stable releases of strongswan consider to be broken as they have been cracked:

   • https://wiki.strongswan.org/projects/strongswan/wiki/IKEv1CipherSuites

See the 'IPsec IKEv1 ciphers' section on the following page on how to query your VPN server for a list of supported ciphers and how to specify legacy ciphers in the Phase 1 and Phase 2 algorithm text boxes of the advanced section of the IPsec dialog box.

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2. Issue with not stopping system xl2tpd service, see:

   • https://github.com/nm-l2tp/network-manager-l2tp#issue-with-not-stopping-system-xl2tpd-service

If you are having IPsec issues with strongswan and network-manger-l2tp, you could try installing and using libreswan instead with:

sudo apt install libreswan

Also have a look at the following page for other issues:

• https://github.com/nm-l2tp/network-manager-l2tp

A backport of network-manager-l2tp packages from Debian Sid and Ubuntu 17.10 (Artful Aardvark) can be found here:

• https://launchpad.net/~nm-l2tp/+archive/ubuntu/network-manager-l2tp