FireBrick Road Warrior strongSwan

This example uses strongSwan on Debian, but the config would suit other flavors once you've installed the package(s).

Install Packages

$ sudo apt-get install strongswan libcharon-extra-plugins

libcharon-extra-plugins is needed for the eap-identity plugin which is required to connect to the FireBrick. The plugin is loaded automatically, so you don't need to change any config files (normally you'd have to change the "load =" statement in strongswan.conf).

Certificate

Download your CA certificate from the FireBrick, and copy to /etc/ipsec.d/cacerts/ on your client box. Strongswan shouldn't mind if PEM or DER.

strongSwan Config

Add your user to: /etc/ipsec.secrets:

username : EAP "password"

Add your connection to /etc/ipsec.conf:

conn username # Arbitrary name - doesn't have to be username
        left=%defaultroute # Use your default route to the internet
        leftfirewall=yes # Yes as you may be behind firewall/NAT
        leftauth=eap-mschapv2 # Match the EAP method defined on FireBrick
        leftid=@peer-ID # Peer ID as defined in FB IPsec IKE setting
        leftsourceip=%config # Ask for an IP from the roaming pool
        eap_identity=username # Username as in ipsec.secrets and FB config
        right=hostname.example.com # Hostname/IP of FireBrick
        rightauth=pubkey # FireBrick should be set to auth-method Certificate
        rightid=@hostname.example.com # ID of FireBrick
        auto=start # Try to connect immediately on startup

Reload settings:

$ sudo service ipsec reload

That should be it.

Split Tunneling

Split tunnelling being where it uses the machine's default route for internet access, this can often can be useful - you may not want to tunnel your normal non-work browsing/streaming through your company's servers.

Here's some StrongSwan info on split tunnelling: https://wiki.strongswan.org/projects/strongswan/wiki/ForwardingAndSplitTunneling

You use leftsubnet on the strongSwan roadwarrior to determine whether to use the tunnel as default gateway - you'd need leftsubnet=0.0.0.0/0 to ensure all traffic used the tunnel, and leftsubnet=<serverLAN> for split tunnelling.

For example:

        leftsourceip=%config4,%config6
        rightsubnet=0.0.0.0/0,::/0