From 562f47147e332edfd3e830f7ba1668f0883f14fc Mon Sep 17 00:00:00 2001
From: epenet <6771947+epenet@users.noreply.github.com>
Date: Mon, 30 Jun 2025 14:41:42 +0000
Subject: [PATCH] Check badly formatted dhcp addresses in tests

---
 homeassistant/helpers/service_info/dhcp.py | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/homeassistant/helpers/service_info/dhcp.py b/homeassistant/helpers/service_info/dhcp.py
index d46c7a59004..94441749c65 100644
--- a/homeassistant/helpers/service_info/dhcp.py
+++ b/homeassistant/helpers/service_info/dhcp.py
@@ -18,3 +18,9 @@ class DhcpServiceInfo(BaseServiceInfo):
     as a lowercase string without colons.
     eg. "AA:BB:CC:12:34:56" is stored as "aabbcc123456"
     """
+
+    def __post_init__(self) -> None:
+        """Post-init processing."""
+        # Ensure macaddress is always a lowercase string without colons
+        if self.macaddress != self.macaddress.lower().replace(":", ""):
+            raise ValueError("macaddress is not correctly formatted")