Red Hat Summit Red Hat SummitSupportConsoleDevelopersStart a trialContact

16.2.2. IPsec Interfaces

The following example shows the ifcfg file for a network-to-network IPsec connection for LAN A. The unique name to identify the connection in this example is ipsec1, so the resulting file is named /etc/sysconfig/network-scripts/ifcfg-ipsec1. 
TYPE=IPsec
ONBOOT=yes
IKE_METHOD=PSK
SRCNET=192.168.1.0/24
DSTNET=192.168.2.0/24
DST=X.X.X.X
Copy to Clipboard Toggle word wrap
In the example above, X.X.X.X is the publicly routable IP address of the destination IPsec router.
Below is a listing of the configurable parameters for an IPsec interface:
DST=<address>
where <address> is the IP address of the IPsec destination host or router. This is used for both host-to-host and network-to-network IPsec configurations.
DSTNET=<network>
where <network> is the network address of the IPsec destination network. This is only used for network-to-network IPsec configurations.
SRC=<address>
where <address> is the IP address of the IPsec source host or router. This setting is optional and is only used for host-to-host IPsec configurations.
SRCNET=<network>
where <network> is the network address of the IPsec source network. This is only used for network-to-network IPsec configurations.
TYPE=<interface-type>
where <interface-type> is IPSEC. Both applications are part of the ipsec-tools package.
If manual key encryption with IPsec is being used, refer to /usr/share/doc/initscripts-<version-number>/sysconfig.txt (replace <version-number> with the version of the initscripts package installed) for configuration parameters.
The racoon IKEv1 key management daemon negotiates and configures a set of parameters for IPSec. It can use preshared keys, RSA signatures, or GSS-API. If racoon is used to automatically manage key encryption, the following options are required:
IKE_METHOD=<encryption-method>
where <encryption-method> is either PSK, X509, or GSSAPI. If PSK is specified, the IKE_PSK parameter must also be set. If X509 is specified, the IKE_CERTFILE parameter must also be set.
IKE_PSK=<shared-key>
where <shared-key> is the shared, secret value for the PSK (preshared keys) method.
IKE_CERTFILE=<cert-file>
where <cert-file> is a valid X.509 certificate file for the host.
IKE_PEER_CERTFILE=<cert-file>
where <cert-file> is a valid X.509 certificate file for the remote host.
IKE_DNSSEC=<answer>
where <answer> is yes. The racoon daemon retrieves the remote host's X.509 certificate via DNS. If a IKE_PEER_CERTFILE is specified, do not include this parameter.
For more information about the encryption algorithms available for IPsec, refer to the setkey man page. For more information about racoon, refer to the racoon and racoon.conf man pages.
Back to top
Red Hat logoGithubredditYoutubeTwitter

Learn

Try, buy, & sell

Communities

About Red Hat Documentation

We help Red Hat users innovate and achieve their goals with our products and services with content they can trust. Explore our recent updates.

Making open source more inclusive

Red Hat is committed to replacing problematic language in our code, documentation, and web properties. For more details, see the Red Hat Blog.

About Red Hat

We deliver hardened solutions that make it easier for enterprises to work across platforms and environments, from the core datacenter to the network edge.

Theme

© 2025 Red Hat