NAME

       ip-tunnel - tunnel configuration

SYNOPSIS

       ip [ OPTIONS ] tunnel  { COMMAND | help }

       ip tunnel { add | change | del | show | prl } [ NAME ]
               [ mode MODE ] [ remote ADDR ] [ local ADDR ]
               [ [i|o]seq ] [ [i|o]key KEY ] [ [i|o]csum ] ]
               [ encaplimit ELIM ] [ ttl TTL ]
               [ tos TOS ] [ flowlabel FLOWLABEL ]
               [ prl-default ADDR ] [ prl-nodefault ADDR ] [ prl-delete ADDR ]
               [ [no]pmtudisc ] [ dev PHYS_DEV ] [ dscp inherit ]

       MODE :=  { ipip | gre | sit | isatap | ip6ip6 | ipip6 | any }

       ADDR := { IP_ADDRESS | any }

       TOS := { NUMBER | inherit }

       ELIM := { none | 0..255 }

       TTL := { 1..255 | inherit }

       KEY := { DOTTED_QUAD | NUMBER }

       TIME := NUMBER[s|ms]

DESCRIPTION

       tunnel objects are tunnels, encapsulating packets in IP packets and
       then sending them over the IP infrastructure.  The encapulating (or
       outer) address family is specified by the -f option.  The default is
       IPv4.

   ip tunnel add - add a new tunnel
   ip tunnel change - change an existing tunnel
   ip tunnel delete - destroy a tunnel
       name NAME (default)
              select the tunnel device name.

       mode MODE
              set the tunnel mode. Available modes depend on the encapsulating
              address family.
              Modes for IPv4 encapsulation available: ipip, sit, isatap and
              gre.
              Modes for IPv6 encapsulation available: ip6ip6, ipip6 and any.

       remote ADDRESS
              set the remote endpoint of the tunnel.

       local ADDRESS
              set the fixed local address for tunneled packets.  It must be an
              address on another interface of this host.

       ttl N  set a fixed TTL N on tunneled packets.  N is a number in the
              range 1--255. 0 is a special value meaning that packets inherit
              the TTL value.  The default value for IPv4 tunnels is: inherit.
              The default value for IPv6 tunnels is: 64.

       tos T

       dsfield T

       tclass T
              set a fixed TOS (or traffic class in IPv6) T on tunneled
              packets.  The default value is: inherit.

       dev NAME
              bind the tunnel to the device NAME so that tunneled packets will
              only be routed via this device and will not be able to escape to
              another device when the route to endpoint changes.

       nopmtudisc
              disable Path MTU Discovery on this tunnel.  It is enabled by
              default.  Note that a fixed ttl is incompatible with this
              option: tunnelling with a fixed ttl always makes pmtu discovery.

       key K

       ikey K

       okey K ( only GRE tunnels ) use keyed GRE with key K. K is either a
              number or an IP address-like dotted quad.  The key parameter
              sets the key to use in both directions.  The ikey and okey
              parameters set different keys for input and output.

       csum, icsum, ocsum
              ( only GRE tunnels ) generate/require checksums for tunneled
              packets.  The ocsum flag calculates checksums for outgoing
              packets.  The icsum flag requires that all input packets have
              the correct checksum.  The csum flag is equivalent to the
              combination icsum ocsum.

       seq, iseq, oseq
              ( only GRE tunnels ) serialize packets.  The oseq flag enables
              sequencing of outgoing packets.  The iseq flag requires that all
              input packets are serialized.  The seq flag is equivalent to the
              combination iseq oseq.  It isn't work. Don't use it.

       dscp inherit
              ( only IPv6 tunnels ) Inherit DS field between inner and outer
              header.

       encaplim ELIM
              ( only IPv6 tunnels ) set a fixed encapsulation limit.  Default
              is 4.

       flowlabel FLOWLABEL
              ( only IPv6 tunnels ) set a fixed flowlabel.

   ip tunnel prl - potential router list (ISATAP only)
       dev NAME
              mandatory device name.

       prl-default ADDR

       prl-nodefault ADDR

       prl-delete ADDR
              Add or delete ADDR as a potential router or default router.

   ip tunnel show - list tunnels
       This command has no arguments.

SEE ALSO

       ip(8)

AUTHOR

       Original Manpage by Michail Litvak <mci@owl.openwall.com>