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if_ipsec(4) FreeBSD Kernel Interfaces Manual if_ipsec(4)
NAME
if_ipsec - IPsec virtual tunneling interface
SYNOPSIS
The if_ipsec network interface is a part of the FreeBSD IPsec
implementation. To compile it into the kernel, place this line in the
kernel configuration file:
options IPSEC
It can also be loaded as part of the ipsec kernel module if the kernel
was compiled with
options IPSEC_SUPPORT
DESCRIPTION
The if_ipsec network interface is targeted for creating route-based VPNs.
It can tunnel IPv4 and IPv6 traffic over either IPv4 or IPv6 and secure
it with ESP.
if_ipsec interfaces are dynamically created and destroyed with the
ifconfig(8) create and destroy subcommands. The administrator must
configure IPsec tunnel endpoint addresses. These addresses will be used
for the outer IP header of ESP packets. The administrator can also
configure the protocol and addresses for the inner IP header with
ifconfig(8), and modify the routing table to route the packets through
the if_ipsec interface.
When the if_ipsec interface is configured, it automatically creates
special security policies. These policies can be used to acquire
security associations from the IKE daemon, which are needed for
establishing an IPsec tunnel. It is also possible to create needed
security associations manually with the setkey(8) utility.
Each if_ipsec interface has an additional numeric configuration option
reqid id. This id is used to distinguish traffic and security policies
between several if_ipsec interfaces. The reqid can be specified on
interface creation and changed later. If not specified, it is
automatically assigned. Note that changing reqid will lead to generation
of new security policies, and this may require creating new security
associations.
EXAMPLES
The example below shows manual configuration of an IPsec tunnel between
two FreeBSD hosts. Host A has the IP address 192.168.0.3, and host B has
the IP address 192.168.0.5.
On host A:
ifconfig ipsec0 create reqid 100
ifconfig ipsec0 inet tunnel 192.168.0.3 192.168.0.5
ifconfig ipsec0 inet 172.16.0.3/16 172.16.0.5
setkey -c
add 192.168.0.3 192.168.0.5 esp 10000 -m tunnel -u 100 -E rijndael-cbc "VerySecureKey!!1";
add 192.168.0.5 192.168.0.3 esp 10001 -m tunnel -u 100 -E rijndael-cbc "VerySecureKey!!2";
^D
add 192.168.0.5 192.168.0.3 esp 10001 -m tunnel -u 200 -E rijndael-cbc "VerySecureKey!!2";
^D
Note the value 100 on host A and value 200 on host B are used as reqid.
The same value must be used as identifier of the policy entry in the
setkey(8) command.
SEE ALSO
gif(4), gre(4), ipsec(4), ifconfig(8), setkey(8)
AUTHORS
Andrey V. Elsukov <ae@FreeBSD.org>
FreeBSD 14.0-RELEASE-p11 February 6, 2017 FreeBSD 14.0-RELEASE-p11