Tinc

Tinc is a simple-to-use VPN software. It differs from other VPN implementations by building a mesh network between clients. This is useful for connecting two networks using a single VPN server without running traffic via the server.

After configuration changes, the best way to restart tinc is ifdown vpn; ifup vpn

Tinc logs to /var/log/daemon.log

Problems

When experiencing the issue that tinc will only sometimes connect to a server, and there are log messages like the following, then it might be that the ping timeout is too small.
```
Timeout from vpn (VPN_SERVER_IP port 655) during authentication
```
To solve this issue, increase the ping timeout in tinc's client configuration file, i.e. put the following line in /etc/tinc/<net>/tinc.conf:
```
PingTimeout = 10
```
If your host connects to vpn.antiguru.de via ipv6, no edges to ipv4 hosts will be created. You have to force using ipv4 on your tinc host by setting the Address in the key file, like Address = vpn4.antiguru.de, otherwise all traffic will have to pass through vpn.antiguru.de, which should be avoided.