If you are using an OpenVZ based VPS then you will need to use this as OpenVZ does not permit persistent tunnels.
Create a cjdns user:
sudo useradd cjdns
Create a new TUN device and give the cjdns user authority to access it:
sudo /sbin/ip tuntap add mode tun user cjdns dev cjdroute0
Run those commands to prepare your TUN device:
sudo /sbin/ip addr add <your ipv6 address>/8 dev cjdroute0
sudo /sbin/ip link set mtu 1312 dev cjdroute0
sudo /sbin/ip link set cjdroute0 up
These commands should be executed as root now every time the system restarts. You might also want to place these commands in /etc/rc.local if your system supports it.
If you see an error when running /sbin/ip, your version of iproute2 might be old.
sudo /sbin/ip tuntap add mode tun user cjdns
Object "tuntap" is unknown, try "ip help".
The fix: for now grab a copy of a newer ip binary and copy it to your home
directory. Replacing the system binaries is not likely a good idea.
sudo -u cjdns ./cjdroute < cjdroute.conf
To delete a tunnel, use this command:
sudo /sbin/ip tuntap del mode tun <name of tunnel>