Cross reference tap(4) and tun(4) and include a short explanation as

to how they differ.  This will assist users in selecting which interface
is more appropriate for their purposes.

Approved by:	grog (co-mentor)
MFC after:	2 week

2 files changed, 27 insertions, 3 deletions

diff --git a/share/man/man4/tap.4 b/share/man/man4/tap.4
index d68dab3..229de60 100644
--- a/share/man/man4/tap.4
+++ b/share/man/man4/tap.4
@@ -1,7 +1,7 @@
 .\" $FreeBSD$
 .\" Based on PR#2411
 .\"
-.Dd November 4, 2014
+.Dd November 30, 2014
 .Dt TAP 4
 .Os
 .Sh NAME
@@ -34,6 +34,17 @@ or a terminal for
 and a character-special device
 .Dq control
 interface.
+A client program transfers Ethernet frames to or from the 
+.Nm
+.Dq control
+interface.
+The
+.Xr tun 4
+interface provides similar functionality at the network layer:
+a client will transfer IP (by default) packets to or from a
+.Xr tun 4
+.Dq control
+interface.
 .Pp
 The network interfaces are named
 .Dq Li tap0 ,
@@ -314,4 +325,5 @@ VMware
 .El
 .Sh SEE ALSO
 .Xr inet 4 ,
-.Xr intro 4
+.Xr intro 4 ,
+.Xr tun 4
diff --git a/share/man/man4/tun.4 b/share/man/man4/tun.4
index b5139a7..0b88b72 100644
--- a/share/man/man4/tun.4
+++ b/share/man/man4/tun.4
@@ -2,7 +2,7 @@
 .\" $FreeBSD$
 .\" Based on PR#2411
 .\"
-.Dd February 4, 2007
+.Dd November 30, 2014
 .Dt TUN 4
 .Os
 .Sh NAME
@@ -35,6 +35,17 @@ or a terminal for
 and a character-special device
 .Dq control
 interface.
+A client program transfers IP (by default) packets to or from the 
+.Nm
+.Dq control
+interface.
+The
+.Xr tap 4
+interface provides similar functionality at the Ethernet layer:
+a client will transfer Ethernet frames to or from a
+.Xr tap 4
+.Dq control
+interface.
 .Pp
 The network interfaces are named
 .Dq Li tun0 ,
@@ -307,6 +318,7 @@ them pile up.
 .Xr inet 4 ,
 .Xr intro 4 ,
 .Xr pty 4 ,
+.Xr tap 4 ,
 .Xr ifconfig 8
 .Sh AUTHORS
 This manual page was originally obtained from