I personally prefer using 'Auto Proxy Discovery' rather than 'Automatic Proxy Configuration'. (I should since I personally got Apple to add this feature several years ago. 🙂)
'Auto Proxy Discovery' is Apple's name for Web Proxy Auto-Discovery aka WPAD which is a feature actually invented by Microsoft! With this a client device will check via either DHCP or DNS to try and 'automatically' find the proxy PAC details. With DHCP it uses DHCP option code 252 which will contain the URL, with DNS it will try http://wpad.yourdomain.com/wpad.dat the DHCP option has preference over DNS.
Apple's own DHCP server should be able to provide DHCP option codes like 252, this was another feature I got them to do several years ago. You will have to manually edit the /etc/bootpd.plist file. If you are going to use Apple's DHCP server for this then you might want to see http://jelockwood.blogspot.co.uk/2013/06/dhcp-server-on-os-x-server.html
I am not using Profile Manager to turn on this setting instead I run the following script as part of the initial configuration of a Mac.
#!/bin/bash
i=1
while [ $i -le 10 ]
do
mainInt=$(/usr/sbin/networksetup -listnetworkserviceorder | awk '{if(a-->0){print;next}} /\('$i'\)/{a=1}')
# If type of network interface is Ethernet and therefore not WiFi or other
if [[ $mainInt == *"Ethernet"* ]]
then
# friendly name used for networksetup command
friendly=$(/usr/sbin/networksetup -listnetworkserviceorder | awk -F'\\) ' '/\('$i'\)/ {print $2}');
# get interface id e.g. en0
device=$(echo "$mainInt" | awk -F': ' '/Ethernet/ {print $3}' | sed 's/.$//');
# check to see if interface is configured for DHCP or manual configuration
iptype=$(/usr/sbin/networksetup -getinfo "$friendly" | awk 'NR == 1 || /DHCP/');
# Check if interface using DHCP configuration, only worth setting auto proxy if DHCP as it used DHCP to learn proxy server setting
if [[ $iptype == "DHCP Configuration" ]]
then
# turn auto-proxy discovery on
/usr/sbin/networksetup -setproxyautodiscovery "$friendly" on;
fi
fi
(( i++ ))
done
exit 0
