diff --git a/doc/ipv6.texi b/doc/ipv6.texi
index de067e0..d4ef45a 100644
--- a/doc/ipv6.texi
+++ b/doc/ipv6.texi
@@ -62,23 +62,24 @@
 @end itemize
 @end deffn
 
-@deffn {Interface Command} {ipv6 nd ra-interval SECONDS} {}
-@deffnx {Interface Command} {no ipv6 nd ra-interval} {}
+@deffn {Interface Command} {ipv6 nd ra-interval <1-1800>} {}
+@deffnx {Interface Command} {no ipv6 nd ra-interval [<1-1800>]} {}
 The  maximum  time allowed between sending unsolicited multicast router
-advertisements from the interface, in seconds. Must be no less than 3 seconds.
+advertisements from the interface, in seconds.
 
 Default: @code{600}
 @end deffn
 
-@deffn {Interface Command} {ipv6 nd ra-interval msec MILLISECONDS} {}
-@deffnx {Interface Command} {no ipv6 nd ra-interval msec} {}
+@deffn {Interface Command} {ipv6 nd ra-interval msec <70-1800000>} {}
+@deffnx {Interface Command} {no ipv6 nd ra-interval [msec <70-1800000>]} {}
 The  maximum  time allowed between sending unsolicited multicast router
-advertisements from the interface, in milliseconds. Must be no less than 30 milliseconds.
+advertisements from the interface, in milliseconds.
 
 Default: @code{600000}
 @end deffn
-@deffn {Interface Command} {ipv6 nd ra-lifetime SECONDS} {}
-@deffnx {Interface Command} {no ipv6 nd ra-lifetime} {}
+
+@deffn {Interface Command} {ipv6 nd ra-lifetime <0-9000>} {}
+@deffnx {Interface Command} {no ipv6 nd ra-lifetime [<0-9000>]} {}
 The value to be placed in the Router Lifetime field of router advertisements
 sent from the interface, in seconds. Indicates the usefulness of the router
 as a default router on this interface. Setting the value to zero indicates
@@ -89,12 +90,12 @@
 Default: @code{1800}
 @end deffn
 
-@deffn {Interface Command} {ipv6 nd reachable-time MILLISECONDS} {}
-@deffnx {Interface Command} {no ipv6 nd reachable-time} {}
+@deffn {Interface Command} {ipv6 nd reachable-time <1-3600000>} {}
+@deffnx {Interface Command} {no ipv6 nd reachable-time [<1-3600000>]} {}
 The value to be placed in the Reachable Time field in the Router Advertisement
 messages sent by the router, in milliseconds. The configured time enables the
 router to detect unavailable neighbors. The value zero means unspecified (by
-this router). Must be no greater than @code{3,600,000} milliseconds (1 hour).
+this router).
 
 Default: @code{0}
 @end deffn
@@ -126,18 +127,20 @@
 Default: not set
 @end deffn
 
-@deffn {Interface Command} {ipv6 nd home-agent-preference} {}
-@deffnx {Interface Command} {no ipv6 nd home-agent-preference} {}
+@deffn {Interface Command} {ipv6 nd home-agent-preference <0-65535>} {}
+@deffnx {Interface Command} {no ipv6 nd home-agent-preference [<0-65535>]} {}
 The value to be placed in Home Agent Option, when Home Agent config flag is set, 
-which indicates to hosts Home Agent preference.
+which indicates to hosts Home Agent preference. The default value of 0 stands
+for the lowest preference possible.
 
 Default: 0
 @end deffn
 
-@deffn {Interface Command} {ipv6 nd home-agent-lifetime} {}
-@deffnx {Interface Command} {no ipv6 nd home-agent-lifetime} {}
++@deffn {Interface Command} {ipv6 nd home-agent-lifetime <0-65520>} {}
++@deffnx {Interface Command} {no ipv6 nd home-agent-lifetime [<0-65520>]} {}
 The value to be placed in Home Agent Option, when Home Agent config flag is set, 
-which indicates to hosts Home Agent Lifetime. A value of 0 means to place Router Lifetime value.
+which indicates to hosts Home Agent Lifetime. The default value of 0 means to
+place the current Router Lifetime value.
 
 Default: 0
 @end deffn
@@ -151,7 +154,7 @@
 @end deffn
 
 @deffn {Interface Command} {ipv6 nd router-preference (high|medium|low)} {}
-@deffnx {Interface Command} {no ipv6 nd router-preference} {}
+@deffnx {Interface Command} {no ipv6 nd router-preference [(high|medium|low)]} {}
 Set default router preference in IPv6 router advertisements per RFC4191.
 
 Default: medium