Proxy Configurations via JSS

This is the scripted solution we are using, populate variables as required. It's only turning things on so you might need a variation to turn things back off.

#!/bin/bash
IP_Subnet=""
Search_Domain=""
Bypass_Domain=""
if [ "$(sw_vers -productVersion | awk -F "." '{print $2}')" -gt 6 ]; then
    Network_Services=$(/usr/sbin/networksetup -listallnetworkservices | awk '!/*/ && !/Bluetooth/')
    IFS=$'
'
    for Network_Service in ${Network_Services}; do
    echo checking $Network_Service
        if [ "$(/usr/sbin/networksetup -getinfo "$Network_Service" | awk '/'$IP_Subnet'/ && /IP address:/')" ];then
            echo $Network_Service needs to be checked

            if [[ "$(/usr/sbin/networksetup -getproxyautodiscovery "$Network_Service" | awk /Off/)" ]]; then
            echo setproxyautodiscovery
            /usr/sbin/networksetup -setproxyautodiscovery "$Network_Service" On
            fi

            if [[ "$(/usr/sbin/networksetup -getinfo "$Network_Service" | awk '/IPv6: On/')" ]]; then
            echo setv6off
            /usr/sbin/networksetup -setv6off "$Network_Service"
            fi

            if [[ -z "$(/usr/sbin/networksetup -getsearchdomains "$Network_Service" | awk /$Search_Domain/)" ]]; then
            echo setsearchdomains
            /usr/sbin/networksetup -setsearchdomains "$Network_Service" $Search_Domain
            fi

            if [[ -z "$(/usr/sbin/networksetup -getproxybypassdomains "$Network_Service" | awk /$Bypass_Domain/)" ]]; then
            echo setproxybypassdomains
            /usr/sbin/networksetup -setproxybypassdomains "$Network_Service" "*.$Bypass_Domain"
            fi
        fi
    done
fi

There are various methods to achieve it however my preferred option would be to create the appropriate configuration policies and scope them with a target group of "All Computers" and limit it to a network segment.