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.\"     Title: IPSEC_TNCFG
.\"    Author: [FIXME: author] [see http://docbook.sf.net/el/author]
.\" Generator: DocBook XSL Stylesheets v1.75.2 <http://docbook.sf.net/>
.\"      Date: 10/06/2010
.\"    Manual: [FIXME: manual]
.\"    Source: [FIXME: source]
.\"  Language: English
.\"
.TH "IPSEC_TNCFG" "5" "10/06/2010" "[FIXME: source]" "[FIXME: manual]"
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.SH "NAME"
ipsec_tncfg \- lists IPSEC virtual interfaces attached to real interfaces
.SH "SYNOPSIS"
.HP \w'\fBipsec\fR\ 'u
\fBipsec\fR \fItncfg\fR
.br
\fIcat/proc/net/ipsec_tncfg\fR
.SH "OBSOLETE"
.PP
Note that tncfg is only supported on the classic KLIPS stack\&. It is not supported on any other stack and will be completely removed in future versions\&. A replacement command still needs to be designed
.SH "DESCRIPTION"
.PP
/proc/net/ipsec_tncfg
is a read\-only file which lists which IPSEC virtual interfaces are attached to which real interfaces, through which packets will be forwarded once processed by IPSEC\&.
.PP
Each line lists one ipsec I/F\&. A table entry consists of:
.PP
+
.RS 4
an ipsec virtual I/F name
.RE
.PP
+
.RS 4
a visual and machine parsable separator \'\->\', separating the virtual I/F and the physical I/F,
.RE
.PP
+
.RS 4
a physical I/F name, to which the ipsec virtual I/F is attached or NULL if it is not attached,
.RE
.PP
+
.RS 4
the keyword
\fBmtu=\fR,
.RE
.PP
+
.RS 4
the MTU of the ipsec virtual I/F,
.RE
.PP
+
.RS 4
the automatically adjusted effective MTU for PMTU discovery, in brackets,
.RE
.PP
+
.RS 4
a visual and machine parsable separator \'\->\', separating the virtual I/F MTU and the physical I/F MTU,
.RE
.PP
+
.RS 4
the MTU of the attached physical I/F\&.
.RE
.SH "EXAMPLES"
.PP
\fBipsec2 \-> eth3 mtu=16260(1443) \-> 1500\fR
.RS 4
.RE
.PP
shows that virtual device
\fBipsec2\fR
with an MTU of
16260
is connected to physical device
\fBeth3\fR
with an MTU of
1500
and that the effective MTU as a result of PMTU discovery has been automatically set to
1443\&.
.PP
\fBipsec0 \-> wvlan0 mtu=1400(16260) \-> 1500\fR
.RS 4
.RE
.PP
shows that virtual device
\fBipsec0\fR
with an MTU of
1400
is connected to physical device
\fBwvlan0\fR
with an MTU of
1500
and no PMTU packets have gotten far enough to bump down the effective MTU from its default of 16260\&.
.PP
\fBipsec3 \-> NULL mtu=0(0) \-> 0\fR
.RS 4
.RE
.PP
shows that virtual device
\fBipsec3\fR
is not connected to any physical device\&.
.SH "FILES"
.PP
/proc/net/ipsec_tncfg, /usr/local/bin/ipsec
.SH "SEE ALSO"
.PP
ipsec(8), ipsec_manual(8), ipsec_eroute(5), ipsec_spi(5), ipsec_spigrp(5), ipsec_klipsdebug(5), ipsec_tncfg(8), ipsec_version(5), ipsec_pf_key(5)
.SH "HISTORY"
.PP
Written for the Linux FreeS/WAN project <\m[blue]\fBhttp://www\&.freeswan\&.org/\fR\m[]> by Richard Guy Briggs\&.