From 1785508ecc8fd79cad853c925154ac2a04da2293 Mon Sep 17 00:00:00 2001
From: weilin <weilin@e0a8ed71-7df4-0310-8962-fdc924857419>
Date: Tue, 2 Aug 2011 08:04:42 +0000
Subject: [PATCH] Added a description of ICMPv6 Neighbor Discovery.

---
 docs/refguide.xml | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/docs/refguide.xml b/docs/refguide.xml
index 1e656bc91..f5c625dea 100644
--- a/docs/refguide.xml
+++ b/docs/refguide.xml
@@ -856,6 +856,10 @@ you would expect.</para>
           for any of the targets which are on the same LAN.  If you
           absolutely don't want to do an ARP scan, specify
           <option>--send-ip</option>.</para>
+          
+          <para>For IPv6 (-6 option), <option>-PR</option> uses ICMPv6
+          Neighbor Discovery instead of ARP. Neighbor Discovery, defined
+          in RFC 4861, can be seen as the IPv6 equivalent of ARP.</para>
 
         </listitem>
       </varlistentry>