Avoiding the problem of connect to outside of LAN with L2TP/IPSec on Ubuntu 18.04.

とても困って、原因の特定に２日かかった。疲れた。確定申告したいのに。

The IPSEC tunnel didn’t allow to connect to outside of LAN after apt upgrade because of the problem of solving the names of the servers. I found out the libnss-sysytemd library with the version 237-3ubuntu10.12 caused the bug.

After downgrade it with below command, problem was fixed.

install_list=$(sudo apt list --upgradable | grep 237-3ubuntu10.12 | awk '{print $1}' | sed 's/\/.*//' | sed 's/.*/\0=237-3ubuntu10.11/' | paste -sd ' ' -) 
echo $install_list
sudo apt-get install $(echo $install_list)
install_list=$(sudo apt list --upgradable | grep 237-3ubuntu10.12 | awk '{print $1}' | sed 's/\/.*//' | paste -sd ' ' -) 
sudo apt-mark hold  $(echo $install_list)

Environment

• Strongswan 5.6.2
• pppd version 2.4.7
• xl2tpd-1.3.13
• Ubuntu 18.04 kernel 4.15.0-45-generic

Please let me know where to submit this bug report if you know.