From b5e6b9cb55b5575b5248affef085584dc51f9b09 Mon Sep 17 00:00:00 2001
From: Christian Hesse <mail@eworm.de>
Date: Mon, 16 Mar 2026 11:27:14 +0100
Subject: [PATCH] dhcp-to-dns: support to ignore networks

Closes: https://github.com/eworm-de/routeros-scripts/issues/119
---
 dhcp-to-dns.rsc    | 12 +++++++++---
 doc/dhcp-to-dns.md |  8 ++++++--
 2 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/dhcp-to-dns.rsc b/dhcp-to-dns.rsc
index 74d2e9b3..692403ba 100644
--- a/dhcp-to-dns.rsc
+++ b/dhcp-to-dns.rsc
@@ -72,15 +72,21 @@
       :continue;
     }
 
-    :local Comment ($CommentPrefix . ", macaddress=" . $LeaseVal->"active-mac-address" . ", server=" . $LeaseVal->"server");
-    :local MacDash [ $CleanName ($LeaseVal->"active-mac-address") ];
-    :local HostName [ $CleanName [ $EitherOr ([ $ParseKeyValueStore ($LeaseVal->"comment") ]->"hostname") ($LeaseVal->"host-name") ] ];
     :local Network [ /ip/dhcp-server/network/find where ($LeaseVal->"active-address") in address ];
     :local NetworkVal;
     :if ([ :len $Network ] > 0) do={
       :set NetworkVal [ /ip/dhcp-server/network/get ($Network->0) ];
     }
     :local NetworkInfo [ $ParseKeyValueStore ($NetworkVal->"comment") ];
+
+    :if ($NetworkInfo->"dns-ignore" = true) do={
+      $LogPrint debug $ScriptName ("Lease for " . $LeaseVal->"active-mac-address" . " is in ignored network... Skipping.");
+      :continue;
+    }
+
+    :local Comment ($CommentPrefix . ", macaddress=" . $LeaseVal->"active-mac-address" . ", server=" . $LeaseVal->"server");
+    :local MacDash [ $CleanName ($LeaseVal->"active-mac-address") ];
+    :local HostName [ $CleanName [ $EitherOr ([ $ParseKeyValueStore ($LeaseVal->"comment") ]->"hostname") ($LeaseVal->"host-name") ] ];
     :local NetDomain ([ $IfThenElse ([ :len ($NetworkInfo->"name-extra") ] > 0) ($NetworkInfo->"name-extra" . ".") ] . \
       [ $EitherOr [ $EitherOr ($NetworkInfo->"domain") ($NetworkVal->"domain") ] $Domain ]);
     :local FullA ($MacDash . "." . $NetDomain);
diff --git a/doc/dhcp-to-dns.md b/doc/dhcp-to-dns.md
index a1a211c6..bf0db384 100644
--- a/doc/dhcp-to-dns.md
+++ b/doc/dhcp-to-dns.md
@@ -50,8 +50,12 @@ A bound lease for mac address `00:11:22:33:44:55` with ip address
 `10.0.0.50` would result in an A record `00-11-22-33-44-55.example.com`
 pointing to the given ip address.
 
-Additional options can be given from comment, to add an extra level in
-dns name or define a different domain.
+Additional options can be given from comment, first of all you can opt-out
+for specific networks:
+
+    /ip/dhcp-server/network/add address=10.0.0.0/24 domain=example.com comment="dns-ignore=true";
+
+Use this to add an extra level in dns name or define a different domain.
 
     /ip/dhcp-server/network/add address=10.0.0.0/24 domain=example.com comment="domain=another-domain.com, name-extra=dhcp";