This document assumes that you are using a Linux system (as one should) and a systemd-based system, the latter part is not really a requirement but it just for having things start on system startup.
The following need to be installed:
1.`fastd`
* This is the layer 2 tunnelling daemon we use to link up machines essentially providing a virtual ethernet network between the two nodes we want to link.
* These are both overlay networks that can be used if clear-net access is not possible.
* We recommend you still use them as they can run without internet access too and redundancy is a goal of CRXN and having a diverse peering setup
## Setting up a tunnel
The next step is to setup a tunnel. You will have to contact someone to get the following:
1.`ip:port` pairing details
* The endpoint of their *fastd* instance
2.`public key`
* You will need their public key which will be used to secure the connection to them such that traffic is encrypted (CRXN traffic and babeld router messages)
* Set this to either `ipv4` or `ipv6` depending of the address being used to connect to the remote peer
3.`"<ip>"`
* Set this to the remote peer's fastd address
4.`"port`
* Set this to the remote peer's fastd port
5.`"<peer's public key>"`
* Set this to your peer's public key
The last thing to configure now is to rise the interface up when fastd starts (as it normally doesn't rise it for you), all occurences of `<interfaceName>` here should match the one in the `interface <interfaceName>;` declaration as shown earlier.