From 8471c006dd50ddcf30dc7a7934bc1115b7923937 Mon Sep 17 00:00:00 2001
From: Henri Wahl <2835065+HenriWahl@users.noreply.github.com>
Date: Mon, 20 Feb 2023 18:02:00 +0100
Subject: [PATCH] fix invalid hostname

---
 dhcpy6d/options/option_39.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/dhcpy6d/options/option_39.py b/dhcpy6d/options/option_39.py
index c4a8d9b..ca12457 100644
--- a/dhcpy6d/options/option_39.py
+++ b/dhcpy6d/options/option_39.py
@@ -78,7 +78,7 @@ def build(self, transaction=None, **kwargs):
                 response_string_part = self.convert_to_string(self.number, f'{nos_flags:02x}{fqdn_binary}')
             else:
                 # if no hostname given put something in and force client override
-                fqdn_binary = convert_dns_to_binary('invalid-hostname.{cfg.DOMAIN}')
+                fqdn_binary = convert_dns_to_binary(f'invalid-hostname.{cfg.DOMAIN}')
                 response_string_part = self.convert_to_string(self.number, f'{3:02x}{fqdn_binary}')
             # options in answer to be logged
             options_answer_part = self.number