diff --git a/vm/archlinux-vm.sh b/vm/archlinux-vm.sh
index e5c438ecd..e1ff0eb28 100644
--- a/vm/archlinux-vm.sh
+++ b/vm/archlinux-vm.sh
@@ -372,17 +372,23 @@ function advanced_settings() {
     exit-script
   fi
 
-  if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 "$GEN_MAC" --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z "$MAC1" ]; then
-      MAC="$GEN_MAC"
-      echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+  while true; do
+    if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 "$GEN_MAC" --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$MAC1" ]; then
+        MAC="$GEN_MAC"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+        break
+      fi
+      if [[ "$MAC1" =~ ^([0-9A-Fa-f]{2}:){5}[0-9A-Fa-f]{2}$ ]]; then
+        MAC="$MAC1"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "Invalid MAC address format. Use XX:XX:XX:XX:XX:XX (e.g., AA:BB:CC:DD:EE:FF)." 8 58
     else
-      MAC="$MAC1"
-      echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC1${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
   while true; do
     if VLAN1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Vlan(leave blank for default)" 8 58 --title "VLAN" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
diff --git a/vm/debian-13-vm.sh b/vm/debian-13-vm.sh
index 7cedd9e74..2f3522f16 100644
--- a/vm/debian-13-vm.sh
+++ b/vm/debian-13-vm.sh
@@ -387,17 +387,23 @@ function advanced_settings() {
     exit-script
   fi
 
-  if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 "$GEN_MAC" --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z "$MAC1" ]; then
-      MAC="$GEN_MAC"
-      echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+  while true; do
+    if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 "$GEN_MAC" --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$MAC1" ]; then
+        MAC="$GEN_MAC"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+        break
+      fi
+      if [[ "$MAC1" =~ ^([0-9A-Fa-f]{2}:){5}[0-9A-Fa-f]{2}$ ]]; then
+        MAC="$MAC1"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "Invalid MAC address format. Use XX:XX:XX:XX:XX:XX (e.g., AA:BB:CC:DD:EE:FF)." 8 58
     else
-      MAC="$MAC1"
-      echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC1${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
   while true; do
     if VLAN1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Vlan(leave blank for default)" 8 58 --title "VLAN" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
diff --git a/vm/debian-vm.sh b/vm/debian-vm.sh
index 3f6a1ba13..b7193f04f 100644
--- a/vm/debian-vm.sh
+++ b/vm/debian-vm.sh
@@ -377,17 +377,23 @@ function advanced_settings() {
     exit-script
   fi
 
-  if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 $GEN_MAC --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $MAC1 ]; then
-      MAC="$GEN_MAC"
-      echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+  while true; do
+    if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 $GEN_MAC --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$MAC1" ]; then
+        MAC="$GEN_MAC"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+        break
+      fi
+      if [[ "$MAC1" =~ ^([0-9A-Fa-f]{2}:){5}[0-9A-Fa-f]{2}$ ]]; then
+        MAC="$MAC1"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "Invalid MAC address format. Use XX:XX:XX:XX:XX:XX (e.g., AA:BB:CC:DD:EE:FF)." 8 58
     else
-      MAC="$MAC1"
-      echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC1${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
   while true; do
     if VLAN1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Vlan(leave blank for default)" 8 58 --title "VLAN" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
diff --git a/vm/docker-vm.sh b/vm/docker-vm.sh
index a7fa7dba5..194470a40 100644
--- a/vm/docker-vm.sh
+++ b/vm/docker-vm.sh
@@ -316,16 +316,23 @@ function advanced_settings() {
   fi
 
   # MAC Address
-  if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 $GEN_MAC --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $MAC1 ]; then
-      MAC="$GEN_MAC"
+  while true; do
+    if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 $GEN_MAC --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$MAC1" ]; then
+        MAC="$GEN_MAC"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+        break
+      fi
+      if [[ "$MAC1" =~ ^([0-9A-Fa-f]{2}:){5}[0-9A-Fa-f]{2}$ ]]; then
+        MAC="$MAC1"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "Invalid MAC address format. Use XX:XX:XX:XX:XX:XX (e.g., AA:BB:CC:DD:EE:FF)." 8 58
     else
-      MAC="$MAC1"
+      exit_script
     fi
-    echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
-  else
-    exit_script
-  fi
+  done
 
   # VLAN
   while true; do
diff --git a/vm/haos-vm.sh b/vm/haos-vm.sh
index 1cdac8b27..af0b0af80 100644
--- a/vm/haos-vm.sh
+++ b/vm/haos-vm.sh
@@ -456,17 +456,23 @@ function advanced_settings() {
     exit-script
   fi
 
-  if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 $GEN_MAC --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $MAC1 ]; then
-      MAC="$GEN_MAC"
-      echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+  while true; do
+    if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 $GEN_MAC --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$MAC1" ]; then
+        MAC="$GEN_MAC"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+        break
+      fi
+      if [[ "$MAC1" =~ ^([0-9A-Fa-f]{2}:){5}[0-9A-Fa-f]{2}$ ]]; then
+        MAC="$MAC1"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "Invalid MAC address format. Use XX:XX:XX:XX:XX:XX (e.g., AA:BB:CC:DD:EE:FF)." 8 58
     else
-      MAC="$MAC1"
-      echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC1${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
   while true; do
     if VLAN1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Vlan(leave blank for default)" 8 58 --title "VLAN" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
diff --git a/vm/mikrotik-routeros.sh b/vm/mikrotik-routeros.sh
index 4121a327e..b2ee376cc 100644
--- a/vm/mikrotik-routeros.sh
+++ b/vm/mikrotik-routeros.sh
@@ -439,17 +439,23 @@ function advanced_settings() {
     exit-script
   fi
 
-  if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 $GEN_MAC --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $MAC1 ]; then
-      MAC="$GEN_MAC"
-      echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+  while true; do
+    if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 $GEN_MAC --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$MAC1" ]; then
+        MAC="$GEN_MAC"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+        break
+      fi
+      if [[ "$MAC1" =~ ^([0-9A-Fa-f]{2}:){5}[0-9A-Fa-f]{2}$ ]]; then
+        MAC="$MAC1"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "Invalid MAC address format. Use XX:XX:XX:XX:XX:XX (e.g., AA:BB:CC:DD:EE:FF)." 8 58
     else
-      MAC="$MAC1"
-      echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC1${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
   while true; do
     if VLAN1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Vlan(leave blank for default)" 8 58 --title "VLAN" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
diff --git a/vm/nextcloud-vm.sh b/vm/nextcloud-vm.sh
index cee5829bc..6f14cdbcc 100644
--- a/vm/nextcloud-vm.sh
+++ b/vm/nextcloud-vm.sh
@@ -375,17 +375,23 @@ function advanced_settings() {
     exit-script
   fi
 
-  if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 $GEN_MAC --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $MAC1 ]; then
-      MAC="$GEN_MAC"
-      echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+  while true; do
+    if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 $GEN_MAC --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$MAC1" ]; then
+        MAC="$GEN_MAC"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+        break
+      fi
+      if [[ "$MAC1" =~ ^([0-9A-Fa-f]{2}:){5}[0-9A-Fa-f]{2}$ ]]; then
+        MAC="$MAC1"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "Invalid MAC address format. Use XX:XX:XX:XX:XX:XX (e.g., AA:BB:CC:DD:EE:FF)." 8 58
     else
-      MAC="$MAC1"
-      echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC1${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
   while true; do
     if VLAN1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Vlan(leave blank for default)" 8 58 --title "VLAN" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
diff --git a/vm/owncloud-vm.sh b/vm/owncloud-vm.sh
index c9c9b0a1e..742bebc79 100644
--- a/vm/owncloud-vm.sh
+++ b/vm/owncloud-vm.sh
@@ -376,17 +376,23 @@ function advanced_settings() {
     exit-script
   fi
 
-  if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 $GEN_MAC --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $MAC1 ]; then
-      MAC="$GEN_MAC"
-      echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+  while true; do
+    if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 $GEN_MAC --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$MAC1" ]; then
+        MAC="$GEN_MAC"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+        break
+      fi
+      if [[ "$MAC1" =~ ^([0-9A-Fa-f]{2}:){5}[0-9A-Fa-f]{2}$ ]]; then
+        MAC="$MAC1"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "Invalid MAC address format. Use XX:XX:XX:XX:XX:XX (e.g., AA:BB:CC:DD:EE:FF)." 8 58
     else
-      MAC="$MAC1"
-      echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC1${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
   while true; do
     if VLAN1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Vlan(leave blank for default)" 8 58 --title "VLAN" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
diff --git a/vm/pimox-haos-vm.sh b/vm/pimox-haos-vm.sh
index 75bfaadc1..71981cfb2 100644
--- a/vm/pimox-haos-vm.sh
+++ b/vm/pimox-haos-vm.sh
@@ -311,17 +311,22 @@ function advanced_settings() {
   else
     if [ $exitstatus = 0 ]; then echo -e "${DGN}Using Bridge: ${BGN}$BRG${CL}"; fi
   fi
-  MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 $GEN_MAC --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3)
-  exitstatus=$?
-  if [ -z $MAC1 ]; then
-    MAC="$GEN_MAC"
-    echo -e "${DGN}Using MAC Address: ${BGN}$MAC${CL}"
-  else
-    if [ $exitstatus = 0 ]; then
+  while true; do
+    MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 $GEN_MAC --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3)
+    exitstatus=$?
+    if [ $exitstatus -ne 0 ]; then exit-script; fi
+    if [ -z "$MAC1" ]; then
+      MAC="$GEN_MAC"
+      echo -e "${DGN}Using MAC Address: ${BGN}$MAC${CL}"
+      break
+    fi
+    if [[ "$MAC1" =~ ^([0-9A-Fa-f]{2}:){5}[0-9A-Fa-f]{2}$ ]]; then
       MAC="$MAC1"
       echo -e "${DGN}Using MAC Address: ${BGN}$MAC1${CL}"
+      break
     fi
-  fi
+    whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "Invalid MAC address format. Use XX:XX:XX:XX:XX:XX (e.g., AA:BB:CC:DD:EE:FF)." 8 58
+  done
   while true; do
     VLAN1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Vlan(leave blank for default)" 8 58 --title "VLAN" --cancel-button Exit-Script 3>&1 1>&2 2>&3)
     exitstatus=$?
diff --git a/vm/truenas-vm.sh b/vm/truenas-vm.sh
index 62c81cfeb..a4447b898 100644
--- a/vm/truenas-vm.sh
+++ b/vm/truenas-vm.sh
@@ -420,17 +420,23 @@ function advanced_settings() {
     exit-script
   fi
 
-  if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 $GEN_MAC --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $MAC1 ]; then
-      MAC="$GEN_MAC"
-      echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+  while true; do
+    if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 $GEN_MAC --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$MAC1" ]; then
+        MAC="$GEN_MAC"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+        break
+      fi
+      if [[ "$MAC1" =~ ^([0-9A-Fa-f]{2}:){5}[0-9A-Fa-f]{2}$ ]]; then
+        MAC="$MAC1"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "Invalid MAC address format. Use XX:XX:XX:XX:XX:XX (e.g., AA:BB:CC:DD:EE:FF)." 8 58
     else
-      MAC="$MAC1"
-      echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC1${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
   while true; do
     if VLAN1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Vlan(leave blank for default)" 8 58 --title "VLAN" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
diff --git a/vm/ubuntu2204-vm.sh b/vm/ubuntu2204-vm.sh
index 8c30af1ef..b6e637804 100644
--- a/vm/ubuntu2204-vm.sh
+++ b/vm/ubuntu2204-vm.sh
@@ -372,17 +372,23 @@ function advanced_settings() {
     exit-script
   fi
 
-  if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 $GEN_MAC --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $MAC1 ]; then
-      MAC="$GEN_MAC"
-      echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+  while true; do
+    if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 $GEN_MAC --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$MAC1" ]; then
+        MAC="$GEN_MAC"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+        break
+      fi
+      if [[ "$MAC1" =~ ^([0-9A-Fa-f]{2}:){5}[0-9A-Fa-f]{2}$ ]]; then
+        MAC="$MAC1"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "Invalid MAC address format. Use XX:XX:XX:XX:XX:XX (e.g., AA:BB:CC:DD:EE:FF)." 8 58
     else
-      MAC="$MAC1"
-      echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC1${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
   while true; do
     if VLAN1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Vlan(leave blank for default)" 8 58 --title "VLAN" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
diff --git a/vm/ubuntu2404-vm.sh b/vm/ubuntu2404-vm.sh
index d9b8c844d..911644550 100644
--- a/vm/ubuntu2404-vm.sh
+++ b/vm/ubuntu2404-vm.sh
@@ -375,17 +375,23 @@ function advanced_settings() {
     exit-script
   fi
 
-  if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 $GEN_MAC --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $MAC1 ]; then
-      MAC="$GEN_MAC"
-      echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+  while true; do
+    if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 $GEN_MAC --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$MAC1" ]; then
+        MAC="$GEN_MAC"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+        break
+      fi
+      if [[ "$MAC1" =~ ^([0-9A-Fa-f]{2}:){5}[0-9A-Fa-f]{2}$ ]]; then
+        MAC="$MAC1"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "Invalid MAC address format. Use XX:XX:XX:XX:XX:XX (e.g., AA:BB:CC:DD:EE:FF)." 8 58
     else
-      MAC="$MAC1"
-      echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC1${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
   while true; do
     if VLAN1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Vlan(leave blank for default)" 8 58 --title "VLAN" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
diff --git a/vm/ubuntu2504-vm.sh b/vm/ubuntu2504-vm.sh
index b4a11e955..e448a1e0f 100644
--- a/vm/ubuntu2504-vm.sh
+++ b/vm/ubuntu2504-vm.sh
@@ -374,17 +374,23 @@ function advanced_settings() {
     exit-script
   fi
 
-  if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 $GEN_MAC --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $MAC1 ]; then
-      MAC="$GEN_MAC"
-      echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+  while true; do
+    if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 $GEN_MAC --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$MAC1" ]; then
+        MAC="$GEN_MAC"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+        break
+      fi
+      if [[ "$MAC1" =~ ^([0-9A-Fa-f]{2}:){5}[0-9A-Fa-f]{2}$ ]]; then
+        MAC="$MAC1"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "Invalid MAC address format. Use XX:XX:XX:XX:XX:XX (e.g., AA:BB:CC:DD:EE:FF)." 8 58
     else
-      MAC="$MAC1"
-      echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC1${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
   while true; do
     if VLAN1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Vlan(leave blank for default)" 8 58 --title "VLAN" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
diff --git a/vm/umbrel-os-vm.sh b/vm/umbrel-os-vm.sh
index 443c1c77c..dc4cb13fb 100644
--- a/vm/umbrel-os-vm.sh
+++ b/vm/umbrel-os-vm.sh
@@ -438,17 +438,23 @@ function advanced_settings() {
     exit-script
   fi
 
-  if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 $GEN_MAC --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
-    if [ -z $MAC1 ]; then
-      MAC="$GEN_MAC"
-      echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+  while true; do
+    if MAC1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a MAC Address" 8 58 $GEN_MAC --title "MAC ADDRESS" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then
+      if [ -z "$MAC1" ]; then
+        MAC="$GEN_MAC"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC${CL}"
+        break
+      fi
+      if [[ "$MAC1" =~ ^([0-9A-Fa-f]{2}:){5}[0-9A-Fa-f]{2}$ ]]; then
+        MAC="$MAC1"
+        echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC1${CL}"
+        break
+      fi
+      whiptail --backtitle "Proxmox VE Helper Scripts" --title "INVALID INPUT" --msgbox "Invalid MAC address format. Use XX:XX:XX:XX:XX:XX (e.g., AA:BB:CC:DD:EE:FF)." 8 58
     else
-      MAC="$MAC1"
-      echo -e "${MACADDRESS}${BOLD}${DGN}MAC Address: ${BGN}$MAC1${CL}"
+      exit-script
     fi
-  else
-    exit-script
-  fi
+  done
 
   while true; do
     if VLAN1=$(whiptail --backtitle "Proxmox VE Helper Scripts" --inputbox "Set a Vlan(leave blank for default)" 8 58 --title "VLAN" --cancel-button Exit-Script 3>&1 1>&2 2>&3); then