---
name: "ipsec_tncfg"
section: "8"
platform: "linux"
package: "openswan"
version: "1:2.6.37-3+deb7u1"
release: "Debian 7 (Wheezy)"
platforms: ["linux"]
url: "https://new.carta.tech/ipsec_tncfg"
---

# ipsec\_tncfg(8)

manipulate KLIPS virtual interfaces

## NAME

ipsec\_tncfg - manipulate KLIPS virtual interfaces

## SYNOPSIS

**ipsec** tncfg\
 ipsec tncfg --create *virtual*\
 ipsec tncfg --delete *virtual*\
 ipsec tncfg --attach --virtual *virtual* --physical *physical*\
 ipsec tncfg --detach --virtual *virtual*\
 ipsec tncfg --clear\
 ipsec tncfg --version\
 ipsec tncfg --help

## OBSOLETE

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

## DESCRIPTION

The historical use of *tncfg* is to attach/detach IPsec virtual interfaces (e.g. ipsec0) to/from physical interfaces (e.g. eth0) through which packets will be forwarded once processed by KLIPS.

The modern use of tncfg is to create and delete virtual interfaces known as mastXXX. mast stands for Mooring and XXX.

The form with no additional arguments lists the contents of /proc/net/ipsec\_tncfg. The format of /proc/net/ipsec\_tncfg is discussed in [ipsec\_tncfg(5)](/ipsec_tncfg/5.md).

The **--attach** form attaches the *virtual* interface to the *physical* one.

The **--detach** form detaches the *virtual* interface from whichever physical interface it is attached to.

The **--clear** form clears all the *virtual* interfaces from whichever physical interfaces they were attached to.

Virtual interfaces typically have names like **ipsec0** or **mast0** while physical interfaces typically have names like **eth0** or **ppp0**.

## EXAMPLES

**ipsec tncfg --create mast12**

creates the mast12 device.

**ipsec tncfg --create ipsec4**

creates an ipsec4 device, but does not attach it.

**ipsec tncfg --attach --virtual ipsec0 --physical eth0**

attaches the **ipsec0** virtual device to the **eth0** physical device.

## FILES

/proc/net/ipsec\_tncfg, /usr/local/bin/ipsec

## SEE ALSO

[ipsec(8)](/ipsec/8.md), [ipsec\_manual(8)](/ipsec_manual/8.md), [ipsec\_eroute(8)](/ipsec_eroute/8.md), [ipsec\_spi(8)](/ipsec_spi/8.md), [ipsec\_spigrp(8)](/ipsec_spigrp/8.md), [ipsec\_klipsdebug(8)](/ipsec_klipsdebug/8.md), [ipsec\_tncfg(5)](/ipsec_tncfg/5.md)

## HISTORY

Written for the Linux FreeS/WAN project \<**http://www.freeswan.org/**\> by Richard Guy Briggs.