diff --git a/update-default-route.yml b/update-default-route.yml
new file mode 100644
index 0000000..9b02ae9
--- /dev/null
+++ b/update-default-route.yml
@@ -0,0 +1,28 @@
+---
+- name: Update default gateway
+  hosts: proxmox_nodes
+  become: true
+  vars:
+    new_gateway: "{{ gateway_ip }}"
+
+  tasks:
+    - name: Validate gateway format
+      assert:
+        that:
+          - new_gateway is match("^(?:[0-9]{1,3}\.){3}[0-9]{1,3}$")
+        fail_msg: "Invalid IPv4 address provided."
+
+    - name: Replace gateway line in interfaces file
+      lineinfile:
+        path: /etc/network/interfaces
+        regexp: '^(\s*)gateway\s+'
+        line: "    gateway {{ new_gateway }}"
+        backrefs: yes
+
+    - name: Apply new default route immediately
+      command: ip route replace default via {{ new_gateway }}
+
+    - name: Restart networking
+      systemd:
+        name: networking
+        state: restarted
\ No newline at end of file