The ISP’s internet connection runs on port expecting a 10MB Full-duplex device to be plugged into it. The WAN interface on my pfSense box is a 10/100 NIC, which when uplinked without making any configuration changes, I found that I was only getting about 25% of the capacity I was expecting. The only way to force the WAN interface to 10MB/Full-duplex is via the /conf/config.xml file. There are two way to edit this… one is using vi from SSH.

To enable SSH do this from the PFSense web-interface:
Click System>Advanced>Secure Shell, Enable Secure Shell

Even if you prefer to use the PFSense web-interface to edit your config.xml file (make a backup copy first), the shell came in handy a few times throughout my configuration process. The other option to edit the config file is using the editor in the PFSense web-interface.

The editor is available here:
Diagnostics>Edit File. The Load/Save path is “/conf/config.xml”.

Scroll down until you find the tag. Then remove the lines that start with <media/> and <mediaopt/> and replace them with ones that say this:

<media>10baseT/UTP</media>
<mediaopt>full-duplex</mediaopt>

Then click Save. You can check to see if this took effect by clicking Status, Interfaces. The WAN interface should now read “10baseT/UTP ”. This change should take effect immediately – if not, give the box a reboot (Diagnostics>Reboot System).