Use Unifi USG3 as a client to connect to AirVPN

[Crazyduck 0]

Hi, 
I wanted to connect my Router "Ubiquiti Unifi Security Gateway 3" as a client to an AirVPN server. Sadly the stock firmware serves Openvpn 2.3.2 only, which is not capable of TLS1.2.

Now i was finally able to install OpenVPN 2.4.0 on the USG. I wrote up all steps in the Ubiquiti Forum, see the link below. 

Note: You have to connect with SSH to the router and update some critical common libraries, like libc6. 
As the USG has a USB thumbdrive inside, where the filesystem is stored, a recover in case of a failure is very easy. Just be prepared for this
Link to my post in the Ubiquiti Support Forum.

[OpenSourcerer 1441]

Quote

dpkg  -i libc6_2.19-18+deb8u10_mips.deb

This can be very deadly to the system! NEVER simply replace an existing version of a fundamental librarly like libc only because one program wants a newer one! If you really insist on it, find out which libraries OpenVPN needs (ldd openvpn), then download and extract all those libs from the packages containing them into some location, download and extract the new openvpn binary, too, and then launch it with LD_LIBRARY_PATH=/the/path/to/that/directory /path/to/the/new/openvpn <arguments>.
In case of OpenVPN this isn't even needed, as v2.3 can be used to connect to AirVPN still.