efw-upgrade behind a proxy

The efw-upgrade command will fail for an EFW living on a network that requires use of an HTTP proxy.  To make it work efw-upgrade needs to be configured to use the proxy to download updates and repo data, but there doesn't appear to be any official documentation on how to do this.  EFW uses the Smart Package Manager, and luckily there's good documentation for smart. 

To make efw-upgrade work, use SSH or the console of the EFW to log in as root then run this command:

smart config --set http-proxy=proxyurl

My proxy url looks something like: http://a.b.c.d:8080

WPAD with EFW

My home router is running Endian Firewall Community edition v2.5.1, and I wanted to configure it to support WPAD using DHCP option 252.  The answer is simple but a little harder to find than I expected, so here it is.

Add the following into the "Custom configuration lines" text box on the DHCP Server configuration page in the EFW web-management console, substituting a.b.c.d for the IP Address of your EFW router:

option wpad code 252 = text;
option wpad "http://a.b.c.d/wpad.dat";

In the first line you're telling your DHCP server that option 252 is going to be an ASCII text string with the name wpad.  In the second line you're assigning a string to that option so the server can give it out to clients.  What you're doing here is giving your DHCP clients the URL for a Proxy Auto-Config file, that will tell them the location of the proxy server and possibly some other options.  If you want to check out the PAC file that EFW creates for you, open up that wpad.dat file from your router and take a look at it.

Option 252 is still only a draft, but it's used commonly enough that many DHCP clients and servers implement it.