FireBrick IPsec config

Overview

In this example we are assuming you can allocate some IP addresses on you LAN. You do this by picking a range of addresses and setting up a roaming-pool (see below). You need to ensure the IP range does not clash with devices on the LAN and is not in the DHCP ranges that could allocate to the LAN.

The FireBrick needs a configuration for the connection, and roaming pools and user identities. The connection can be used for any number of devices at once with the same pool of IP addresses; each would have a user name and password defined.

Proxy ARP

You also need to set proxy-arp on the LAN interface settings to allow communications to other devices on your LAN. Alternatively you could set private IP addresses in the pool and set the nat setting. You should probably also consider firewalling rules for traffic to/from IPsec connections.

Proxy ARP setting on the subnet

Configuration

The basic server config is in ipsec-ike containing a connection and roaming entry, e.g.

<ipsec-ike>
 <connection name="server" roaming-pool="roam-pool" auth-method="Certificate" peer-auth-method="EAP" mode="Wait" local-ID="FQDN:server.example.com"/>
 <roaming name="roam-pool" ip="[ranges of LAN IPs]" DNS="[DNS, e.g. 8.8.8.8]"/>
</ipsec-ike>

Each roaming user then needs an eap user record.

 <eap name="fred" full-name="Fred Bloggs" password="[password]" subsystem="IPsec" methods="MSChapV2"/>

Here is how the above three config sections look in the User Interface (UI):

FireBrick SCreenshots
IKE Settings (UI). (Config - Edit - Tunnels - IPsec - Add, IKE connection)
Roaming Pool Settings (UI). (Config - Edit - Tunnels - IPsec - Add, IKE roaming IP pools
EAP User (UI). (Config - Edit - Users - Add, User access control via EAP

Firewall

There are two aspects to Firewalling:

Allowing IPsec traffic in to the FireBrick
Controlling what an IPsec client, once connected, has access to

Allow IPsec traffic in to the FireBrick

See: IPsec_Firewall

Controlling client traffic

You will also want to look at the Firewall on the FireBrick and allow traffic where required, for example, to Allow the IPsec users to connect to the Internet via your PPPoE connections use something like:

   <rule-set name="FromIPSec" source-interface="ipsec" no-match-action="continue">
      <rule name="AllowInternet" target-interface="pppoe" action="accept"/>
   </rule-set>

DNS Servers

If you set the DNS servers in the pool to be the FireBrick's IP address then you will need to allow access. This will be done with:

Firewal rules (port 53 to the FireBrick from IPsec
Editing the DNS Service to allow non-local users, we'd recommend using an Allow list that includes the IPsec clients as well as the LAN clients if they are to also use the FireBrick as their DNS resolver. (Setup - General System Services - DNS)