New net-tools 'ifconfig' command output has change. So 'ifconfig' is replaced by 'ip a'.

conf/main_ipv4.conf.sample

@@ -8,7 +8,11 @@
 # - IPv4 Addresses Gateway
 # ---
 declare -a gateway_ipv4_address_arr
-read -a gateway_ipv4_address_arr <<<$(ifconfig | grep "inet Ad" | awk '{print$2}' | cut -d':' -f2)
+
+_ips="$(ip a | grep "inet " | awk '{print$2}' | cut -d'/' -f1)"
+for _ip in $_ips ; do
+   gateway_ipv4_address_arr+=("$_ip")
+done
 
 
 # =============

conf/main_ipv6.conf.sample

@@ -8,7 +8,11 @@
 # - IPv6 Addresses Gateway
 # ---
 declare -a gateway_ipv6_address_arr
-read -a gateway_ipv6_address_arr <<<$(ifconfig | grep "inet6-Ad" | awk '{print$2}'| cut -d'/' -f1)
+
+_ips="$(ip a | grep "inet6 " | awk '{print$2}' | cut -d'/' -f1)"
+for _ip in $_ips ; do
+   gateway_ipv6_address_arr+=("$_ip")
+done
 
 
 # =============