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 IPSECIt can also be loaded as part of the ipsec
kernel module if the kernel was compiled with
options IPSEC_SUPPORTDESCRIPTION
Theif_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
On host B:
ifconfig ipsec0 create reqid 200 ifconfig ipsec0 inet tunnel 192.168.0.5 192.168.0.3 ifconfig ipsec0 inet 172.16.0.5/16 172.16.0.3 setkey -c add 192.168.0.3 192.168.0.5 esp 10000 -m tunnel -u 200 -E rijndael-cbc "VerySecureKey!!1"; 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
AUTHORS
Andrey V. Elsukov <ae@FreeBSD.org>