ip-tunnel - tunnel configuration

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

iproute2                                           20 Dec 2011                                      IP-TUNNEL(8)

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.

       iptunneladd
              add a new tunnel

       iptunnelchange
              change an existing tunnel

       iptunneldelete
              destroy a tunnel

              nameNAME(default)
                     select the tunnel device name.

              modeMODE
                     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.

              remoteADDRESS
                     set the remote endpoint of the tunnel.

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

              ttlNhoplimitN
                     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 tunnels is: 64.

              tosTdsfieldTtclassT
                     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.

              devNAME
                     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 causes the DF flag
                     to be ignored.

              keyKikeyKokeyK ( onlyGREtunnels ) 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
                     ( onlyGREtunnels ) 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 icsumocsum.

              seq, iseq, oseq
                     ( onlyGREtunnels ) 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 iseqoseq.  Itdoesn'twork.Don'tuseit.encaplimitELIM
                     ( onlyIPv6tunnels ) set a fixed encapsulation limit. Default is 4.

              flowlabelFLOWLABEL
                     ( onlyIPv6tunnels ) set a fixed flowlabel.

              allow-localremote
                     ( onlyIPv6tunnels ) allow remote endpoint on the local host.

       iptunnelprl
              potential router list (ISATAP only)

              devNAME
                     mandatory device name.

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

       iptunnelshow
              list tunnels This command has no arguments.

       ip-tunnel - tunnel configuration

ip(8)

iptunnelhelpip [ OPTIONS ] tunnel { add | change | del | show | prl | 6rd } [ NAME ]
               [ modeMODE ] [ remoteADDR ] [ localADDR ]
               [ [i|o]seq ] [ [i|o]keyKEY ] [ [i|o]csum ] ]
               [ encaplimitELIM ] [ ttl|hoplimitTTL ]
               [ tosTOS ] [ flowlabelFLOWLABEL ]
               [ prl-defaultADDR ] [ prl-nodefaultADDR ] [ prl-deleteADDR ]
               [ 6rd-prefixADDR ] [ 6rd-relay_prefixADDR ] [ 6rd-reset ]
               [ [no]pmtudisc ] [ [no]ignore-df ] [ [no]allow-localremote ]
               [ devPHYS_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 }