From 407d469be919f1841fb3bac49947c758c4a24b67 Mon Sep 17 00:00:00 2001
From: Yuxiang Zhu <vfreex@gmail.com>
Date: Mon, 21 Nov 2022 01:02:54 +0800
Subject: T4832: dhcp: Add dhcp option to signal IPv6-only support

Clients supporting this DHCP option (DHCP option 108, per RFC 8925) will
disable its IPv4 network stack for configured number of seconds
and operate in IPv6-only mode.

Example clients supporting this option including iOS 15+ and macOS 12.0.1+.
---
 interface-definitions/dhcp-server.xml.in | 13 +++++++++++++
 1 file changed, 13 insertions(+)

(limited to 'interface-definitions')

diff --git a/interface-definitions/dhcp-server.xml.in b/interface-definitions/dhcp-server.xml.in
index 8c10ccf99..c1f2fe2fd 100644
--- a/interface-definitions/dhcp-server.xml.in
+++ b/interface-definitions/dhcp-server.xml.in
@@ -357,6 +357,19 @@
                       </leafNode>
                     </children>
                   </tagNode >
+                  <leafNode name="ipv6-only-preferred">
+                    <properties>
+                      <help>Disable IPv4 on IPv6 only hosts (RFC 8925)</help>
+                      <valueHelp>
+                        <format>u32</format>
+                        <description>Seconds</description>
+                      </valueHelp>
+                      <constraint>
+                        <validator name="numeric" argument="--range 0-4294967295"/>
+                      </constraint>
+                      <constraintErrorMessage>Seconds must be between 0 and 4294967295 (49 days)</constraintErrorMessage>
+                    </properties>
+                  </leafNode>
                   <leafNode name="subnet-parameters">
                     <properties>
                       <help>Additional subnet parameters for DHCP server. You must
-- 
cgit v1.2.3