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
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 theipsec-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
, orGSSAPI
. IfPSK
is specified, theIKE_PSK
parameter must also be set. IfX509
is specified, theIKE_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
. Theracoon
daemon retrieves the remote host'sX.509
certificate via DNS. If aIKE_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.