IP-TUNNEL(8)							       Linux							      IP-TUNNEL(8)

NAME

       ip-tunnel - tunnel configuration

SYNOPSIS

       ip tunnel help

       ip [ OPTIONS ] tunnel { add | change | del | show | prl | 6rd } [ NAME ]
	       [ mode MODE ] [ remote ADDR ] [ local ADDR ]
	       [ [i|o]seq ] [ [i|o]key KEY ] [ [i|o]csum ] ]
	       [ encaplimit ELIM ] [ ttl|hoplimit TTL ]
	       [ tos TOS ] [ flowlabel FLOWLABEL ]
	       [ prl-default ADDR ] [ prl-nodefault ADDR ] [ prl-delete ADDR ]
	       [ 6rd-prefix ADDR ] [ 6rd-relay_prefix ADDR ] [ 6rd-reset ]
	       [ [no]pmtudisc ] [ [no]ignore-df ] [ [no]allow-localremote ]
	       [ dev PHYS_DEV ]

       MODE :=	{ ipip | gre | sit | isatap | vti | ip6ip6 | ipip6 | ip6gre | vti6 | any }

       ADDR := { IP_ADDRESS | any }

       TOS := { STRING | 00..ff | inherit | inherit/STRING | inherit/00..ff }

       ELIM := { none | 0..255 }

       TTL := { 1..255 | inherit }

       KEY := { DOTTED_QUAD | NUMBER }

DESCRIPTION

       tunnel objects are tunnels, encapsulating packets in IP packets and then sending them over the IP infrastructure.  The encapsulating (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, vti, and gre.
		     Modes for IPv6 encapsulation available: ip6ip6, ipip6, ip6gre, vti6, 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

	      hoplimit N
		     set a fixed TTL (IPv4) or hoplimit (IPv6) 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 tun-
		     nels is: 64.

	      tos T

	      dsfield T

	      tclass T
		     set the type of service (IPv4) or traffic class (IPv6) field on tunneled packets, which can be specified as either a two-
		     digit hex value (e.g. c0) or a predefined string (e.g. internet).	The value inherit causes the field to be copied from the
		     original IP header. The values inherit/STRING or inherit/00..ff will set the field to STRING or 00..ff when tunneling non-IP
		     packets. The default value is 00.

	      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:
		     tunneling with a fixed ttl always makes pmtu discovery.

	      ignore-df
		     enable IPv4 DF suppression on this tunnel.  Normally datagrams that exceed the MTU will be fragmented; the presence of the DF
		     flag inhibits this, resulting instead in an ICMP Unreachable (Fragmentation Required) message.  Enabling this attribute
		     casues the DF flag to be ignored.

	      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 pack-
		     ets.  The icsum flag requires that all input packets have the correct checksum. The csum flag is equivalent to the combina-
		     tion 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 doesn't work. Don't use it.

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

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

	      allow-localremote
		     ( only IPv6 tunnels ) allow remote endpoint on the local host.

       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>

iproute2							    20 Dec 2011 						      IP-TUNNEL(8)