diff --git a/conf/interfaces.json b/conf/interfaces.json
index 2d483e5..d4bdb12 100644
--- a/conf/interfaces.json
+++ b/conf/interfaces.json
@@ -4,6 +4,6 @@
                 "fd42::/112"
         ],
         "listen_port": "__PORT_WG__",
-        "post_up": "",
-        "post_down": ""
+        "post_up": "iptables -A FORWARD -i %i -j ACCEPT; iptables -A FORWARD -o %i -j ACCEPT; iptables -t nat -A POSTROUTING -o __INTERFACE__ -j MASQUERADE; ip6tables -A FORWARD -i %i -j ACCEPT; ip6tables -A FORWARD -o %i -j ACCEPT; ip6tables -t nat -A POSTROUTING -o __INTERFACE__ -j MASQUERADE; ip link set multicast on dev %i",
+        "post_down": "iptables -D FORWARD -i %i -j ACCEPT; iptables -D FORWARD -o %i -j ACCEPT; iptables -t nat -D POSTROUTING -o __INTERFACE__ -j MASQUERADE; ip6tables -D FORWARD -i %i -j ACCEPT; ip6tables -D FORWARD -o %i -j ACCEPT; ip6tables -t nat -D POSTROUTING -o __INTERFACE__ -j MASQUERADE"
 }
diff --git a/conf/wg0.conf b/conf/wg0.conf
index 8077375..a0d5882 100644
--- a/conf/wg0.conf
+++ b/conf/wg0.conf
@@ -8,5 +8,5 @@ Address = 10.10.10.0/24,fd42::/112
 ListenPort = __PORT_WG__
 PrivateKey = __PRIVATE_KEY__
 MTU = 1450
-PostUp =
-PostDown =
+PostUp = iptables -A FORWARD -i %i -j ACCEPT; iptables -A FORWARD -o %i -j ACCEPT; iptables -t nat -A POSTROUTING -o __INTERFACE__ -j MASQUERADE; ip6tables -A FORWARD -i %i -j ACCEPT; ip6tables -A FORWARD -o %i -j ACCEPT; ip6tables -t nat -A POSTROUTING -o __INTERFACE__ -j MASQUERADE; ip link set multicast on dev %i
+PostDown = iptables -D FORWARD -i %i -j ACCEPT; iptables -D FORWARD -o %i -j ACCEPT; iptables -t nat -D POSTROUTING -o __INTERFACE__ -j MASQUERADE; ip6tables -D FORWARD -i %i -j ACCEPT; ip6tables -D FORWARD -o %i -j ACCEPT; ip6tables -t nat -D POSTROUTING -o __INTERFACE__ -j MASQUERADE
diff --git a/scripts/_common.sh b/scripts/_common.sh
index cb7337e..26317a4 100644
--- a/scripts/_common.sh
+++ b/scripts/_common.sh
@@ -14,6 +14,8 @@ fi
 # dependencies used by the app
 pkg_dependencies="$pkg_headers wireguard-dkms wireguard"
 
+interface=$(ip route | awk '/default/ { print $5 }')
+
 #=================================================
 # PERSONAL HELPERS
 #=================================================
diff --git a/scripts/install b/scripts/install
index 55a9364..e9c0f07 100644
--- a/scripts/install
+++ b/scripts/install
@@ -49,6 +49,7 @@ ynh_script_progression --message="Storing installation settings..." --weight=1
 ynh_app_setting_set --app=$app --key=domain --value=$domain
 ynh_app_setting_set --app=$app --key=path --value=$path_url
 ynh_app_setting_set --app=$app --key=admin --value=$admin
+ynh_app_setting_set --app=$app --key=interface --value=$interface
 
 #=================================================
 # STANDARD MODIFICATIONS
@@ -130,16 +131,15 @@ ynh_replace_string "__USER__" "${app}" /etc/sudoers.d/${app}_ynh
 mkdir -p $final_path/db/server
 
 # Add interface configuration file for the Web UI
-cp ../conf/interfaces.json $final_path/db/server/interfaces.json
-ynh_replace_string --match_string="__PORT_WG__" --replace_string="$port_wg" --target_file="$final_path/db/server/interfaces.json"
+ynh_add_config --template="../conf/interfaces.json" --destination="$final_path/db/server/interfaces.json"
+ynh_delete_file_checksum --file="$final_path/db/server/interfaces.json"
 
 # Create WireGuard configuration directory
 mkdir -p /etc/wireguard
 
 # Add interface configuration file for WireGuard
-cp ../conf/wg0.conf /etc/wireguard/wg0.conf
-ynh_replace_string --match_string="__PORT_WG__" --replace_string="$port_wg" --target_file="/etc/wireguard/wg0.conf"
-ynh_replace_string --match_string="__PRIVATE_KEY__" --replace_string="$(wg genkey)" --target_file="/etc/wireguard/wg0.conf"
+ynh_add_config --template="../conf/wg0.conf" --destination="/etc/wireguard/wg0.conf"
+ynh_delete_file_checksum --file="/etc/wireguard/wg0.conf"
 
 #=================================================
 # SETUP SYSTEMD
diff --git a/scripts/upgrade b/scripts/upgrade
index a026238..684ffae 100644
--- a/scripts/upgrade
+++ b/scripts/upgrade
@@ -187,13 +187,6 @@ systemctl enable --quiet wireguard_ui_conf.service
 # CONFIGURING WIREGUARD
 #=================================================
 
-# Create db directory for securing it later
-mkdir -p $final_path/db/server
-
-# Add interface configuration file
-cp ../conf/interfaces.json $final_path/db/server/interfaces.json
-ynh_replace_string --match_string="__PORT_WG__" --replace_string="$port_wg" --target_file="$final_path/db/server/interfaces.json"
-
 #=================================================
 # GENERIC FINALIZATION
 #=================================================