OpenWrt/LEDE openDNS dynamic ip updater, handles no Internet access state, and !yours openDNS IP conflict, and configures IP filtering as fast as possible, other methods implies few minutes without filtering after reconnecting

99-opendns-update-ip.sh

#!/bin/sh
# Place me in /etc/hotplug.d/iface/99-opendns-update-ip
#configuration start
user="mail@example.com" #email used while registering to opendns
password="pass" #password to opendns , as special chars use _ - (underscore or minus), other specials must be escaped
hostname="home" #label of opendns network 
targetInterface="wan" #interface which has access to Internet, and dynamic ip
#configuration end
[ "$ACTION" = "ifup" ] && [ "$INTERFACE" = $targetInterface ] && {
	logger -s -t opendnsIpChange "$targetInterface is up, updating ip"
	while true;
	do
		result=$(wget -q -O - --no-check-certificate --timeout=10 --user="$user" --password="$password" https://updates.opendns.com/nic/update?hostname=$hostname)
		exit_code=$?
		echo "exit_code = $exit_code"
		echo "result = $result"
		[ "${result/good}" != "$result" ]&& {
			logger -s -t opendnsIpChange "successfully updated IP $result"				
			exit 0
		}
		[ "${result/yours}" != "$result" ]&& {
			logger -s -t opendnsIpChange "IP conflict response: $result"
			logger -s -t opendnsIpChange "restarting wan to change IP"
			ifdown wan
			sleep 1
			ifup wan
			exit 0
		}
		[ $exit_code = 4 ] && {
			echo "no internet connection"
			continue
		}
		logger -s -t opendnsIpChange "not supported response: $result"
		logger -s -t opendnsIpChange "wget exit code: $exit_code"
		logger -s -t opendnsIpChange "retry after 1 minute"
		sleep 61 #minute to do not abuse opendns server in case of wrong result	
	done
}