Module Name: src
Committed By: roy
Date: Sun Sep 27 19:36:54 UTC 2020
Modified Files:
src/share/man/man4: tap.4 tun.4
Log Message:
Note that opening and closing the tun/tap devices affects link state.
And how this influences Duplicate Address Detection.
To generate a diff of this commit:
cvs rdiff -u -r1.14 -r1.15 src/share/man/man4/tap.4
cvs rdiff -u -r1.24 -r1.25 src/share/man/man4/tun.4
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/share/man/man4/tap.4
diff -u src/share/man/man4/tap.4:1.14 src/share/man/man4/tap.4:1.15
--- src/share/man/man4/tap.4:1.14 Sun Sep 27 15:19:04 2020
+++ src/share/man/man4/tap.4 Sun Sep 27 19:36:54 2020
@@ -1,4 +1,4 @@
-.\" $NetBSD: tap.4,v 1.14 2020/09/27 15:19:04 roy Exp $
+.\" $NetBSD: tap.4,v 1.15 2020/09/27 19:36:54 roy Exp $
.\"
.\" Copyright (c) 2004, 2005 The NetBSD Foundation.
.\" All rights reserved.
@@ -159,6 +159,14 @@ ioctl on a
.Dv PF_LINK
socket, as it is not available on
the ioctl handler of the character device interface.
+.Ss LINK STATE
+When an application has opened the
+.Nm
+character device the link is considered up, otherwise down.
+As such, it is best to open the character device once connectivity has
+been established so that Duplicate Address Detection, if applicable,
+can be performed.
+If connectivity is lost, the character device should be closed.
.Sh FILES
.Bl -tag -compact -width /dev/tap[0-9]*
.It Pa /dev/tap
Index: src/share/man/man4/tun.4
diff -u src/share/man/man4/tun.4:1.24 src/share/man/man4/tun.4:1.25
--- src/share/man/man4/tun.4:1.24 Tue Mar 26 09:58:20 2019
+++ src/share/man/man4/tun.4 Sun Sep 27 19:36:54 2020
@@ -1,4 +1,4 @@
-.\" $NetBSD: tun.4,v 1.24 2019/03/26 09:58:20 pgoyette Exp $
+.\" $NetBSD: tun.4,v 1.25 2020/09/27 19:36:54 roy Exp $
.\"
.\" Copyright (c) 1996-2006 The NetBSD Foundation, Inc.
.\" All rights reserved.
@@ -27,7 +27,7 @@
.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
.\" POSSIBILITY OF SUCH DAMAGE.
.\"
-.Dd April 8, 2006
+.Dd September 27, 2020
.Dt TUN 4
.Os
.Sh NAME
@@ -272,6 +272,14 @@ All queued packets are thrown away.
If the interface is up when the data device is not open
output packets are always thrown away rather than letting
them pile up.
+.Ss LINK STATE
+When an application has opened the
+.Nm
+character device the link is considered up, otherwise down.
+As such, it is best to open the character device once connectivity has
+been established so that Duplicate Address Detection, if applicable,
+can be performed.
+If connectivity is lost, the character device should be closed.
.Sh SEE ALSO
.Xr inet 4 ,
.Xr intro 4
