xref: /freebsd/share/man/man4/if_ipsec.4 (revision e0c4386e)
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25.Dd February 6, 2017
26.Dt if_ipsec 4
27.Os
28.Sh NAME
29.Nm if_ipsec
30.Nd IPsec virtual tunneling interface
31.Sh SYNOPSIS
32The
33.Cm if_ipsec
34network interface is a part of the
35.Fx
36IPsec implementation.
37To compile it into the kernel, place this line in the kernel
38configuration file:
39.Bd -ragged -offset indent
40.Cd "options IPSEC"
41.Ed
42.Pp
43It can also be loaded as part of the
44.Cm ipsec
45kernel module if the kernel was compiled with
46.Bd -ragged -offset indent
47.Cd "options IPSEC_SUPPORT"
48.Ed
49.Sh DESCRIPTION
50The
51.Nm
52network interface is targeted for creating route-based VPNs.
53It can tunnel IPv4 and IPv6 traffic over either IPv4 or IPv6 and secure
54it with ESP.
55.Pp
56.Nm
57interfaces are dynamically created and destroyed with the
58.Xr ifconfig 8
59.Cm create
60and
61.Cm destroy
62subcommands.
63The administrator must configure IPsec
64.Cm tunnel
65endpoint addresses.
66These addresses will be used for the outer IP header of ESP packets.
67The administrator can also configure the protocol and addresses for the inner
68IP header with
69.Xr ifconfig 8 ,
70and modify the routing table to route the packets through the
71.Nm
72interface.
73.Pp
74When the
75.Nm
76interface is configured, it automatically creates special security policies.
77These policies can be used to acquire security associations from the IKE daemon,
78which are needed for establishing an IPsec tunnel.
79It is also possible to create needed security associations manually with the
80.Xr setkey 8
81utility.
82.Pp
83Each
84.Nm
85interface has an additional numeric configuration option
86.Cm reqid Ar id .
87This
88.Ar id
89is used to distinguish traffic and security policies between several
90.Nm
91interfaces.
92The
93.Cm reqid
94can be specified on interface creation and changed later.
95If not specified, it is automatically assigned.
96Note that changing
97.Cm reqid
98will lead to generation of new security policies, and this
99may require creating new security associations.
100.Sh EXAMPLES
101The example below shows manual configuration of an IPsec tunnel
102between two FreeBSD hosts.
103Host A has the IP address 192.168.0.3, and host B has the IP address
104192.168.0.5.
105.Pp
106On host A:
107.Bd -literal -offset indent
108ifconfig ipsec0 create reqid 100
109ifconfig ipsec0 inet tunnel 192.168.0.3 192.168.0.5
110ifconfig ipsec0 inet 172.16.0.3/16 172.16.0.5
111setkey -c
112add 192.168.0.3 192.168.0.5 esp 10000 -m tunnel -u 100 -E rijndael-cbc "VerySecureKey!!1";
113add 192.168.0.5 192.168.0.3 esp 10001 -m tunnel -u 100 -E rijndael-cbc "VerySecureKey!!2";
114^D
115.Ed
116.Pp
117On host B:
118.Bd -literal -offset indent
119ifconfig ipsec0 create reqid 200
120ifconfig ipsec0 inet tunnel 192.168.0.5 192.168.0.3
121ifconfig ipsec0 inet 172.16.0.5/16 172.16.0.3
122setkey -c
123add 192.168.0.3 192.168.0.5 esp 10000 -m tunnel -u 200 -E rijndael-cbc "VerySecureKey!!1";
124add 192.168.0.5 192.168.0.3 esp 10001 -m tunnel -u 200 -E rijndael-cbc "VerySecureKey!!2";
125^D
126.Ed
127.Pp
128Note the value 100 on host A and value 200 on host B are used as reqid.
129The same value must be used as identifier of the policy entry in the
130.Xr setkey 8
131command.
132.Sh SEE ALSO
133.Xr gif 4 ,
134.Xr gre 4 ,
135.Xr ipsec 4 ,
136.Xr ifconfig 8 ,
137.Xr setkey 8
138.Sh AUTHORS
139.An Andrey V. Elsukov Aq Mt ae@FreeBSD.org
140