NAME

       tunnel_key - Tunnel metadata manipulation

SYNOPSIS

       tc ... action tunnel_key { unset | SET }

       SET := set src_ip ADDRESS dst_ip ADDRESS id KEY_ID dst_port UDP_PORT [ csum | nocsum ]

DESCRIPTION

       The  tunnel_key  action  combined  with  a  shared  IP  tunnel device, allows to perform IP tunnel en- or
       decapsulation on a packet, reflected by the operation modes UNSET and SET.  The UNSET mode is optional  -
       even  without  using  it,  the metadata information will be released automatically when packet processing
       will be finished.  UNSET function could be used in cases when traffic is forwarded between  two  tunnels,
       where  the  metadata from the first tunnel will be used for encapsulation done by the second tunnel.  SET
       mode requires the source and destination ip ADDRESS and the tunnel key id KEY_ID which will  be  used  by
       the  ip  tunnel  shared  device  to  create  the  tunnel  header. The tunnel_key action is useful only in
       combination with a mirred redirect action to a shared IP tunnel device which will use the  metadata  (for
       SET ) and unset the metadata created by it (for UNSET ).

OPTIONS

       unset  Unset  the  tunnel  metadata  created by the IP tunnel device.  This function is not mandatory and
              might be used only in some specific use cases (as explained above).

       set    Set tunnel metadata to be used by the IP tunnel device. Requires id , src_ip and  dst_ip  options.
              dst_port is optional.

              id     Tunnel ID (for example VNI in VXLAN tunnel)

              src_ip Outer header source IP address (IPv4 or IPv6)

              dst_ip Outer header destination IP address (IPv4 or IPv6)

              dst_port
                     Outer header destination UDP port

              [no]csum
                     Controlls  outer  UDP checksum. When set to csum (which is default), the outer UDP checksum
                     is calculated and included in the packets. When set to nocsum, outer UDP checksum is  zero.
                     Note  that  when  using  zero  UDP  checksums  with IPv6, the other tunnel endpoint must be
                     configured to accept such packets.  In Linux, this would be the udp6zerocsumrx  option  for
                     the VXLAN tunnel interface.

                     If  using nocsum with IPv6, be sure you know what you are doing. Zero UDP checksums provide
                     weaker protection against corrupted packets. See RFC6935 for details.

EXAMPLES

       The following example encapsulates incoming ICMP packets on eth0 into a vxlan tunnel, by setting metadata
       to VNI 11, source IP 11.11.0.1 and destination IP 11.11.0.2, and  by  redirecting  the  packet  with  the
       metadata to device vxlan0, which will do the actual encapsulation using the metadata:

              #tc qdisc add dev eth0 handle ffff: ingress
              #tc filter add dev eth0 protocol ip parent ffff: \
                flower \
                  ip_proto icmp \
                action tunnel_key set \
                  src_ip 11.11.0.1 \
                  dst_ip 11.11.0.2 \
                  id 11 \
                action mirred egress redirect dev vxlan0

       Here  is  an  example  of  the  unset  function:  Incoming  VXLAN  traffic  with outer IP's and VNI 11 is
       decapsulated by vxlan0 and metadata is unset before redirecting to tunl1 device:

              #tc qdisc add dev eth0 handle ffff: ingress
              #tc filter add dev vxlan0 protocol ip parent ffff:   flower \
                     enc_src_ip 11.11.0.2 enc_dst_ip 11.11.0.1 enc_key_id 11   action tunnel_key unset  action mirred egress redirect dev tunl1

SEE ALSO

       tc(8)

iproute2                                           10 Nov 2016      Tunnel metadata manipulation action in tc(8)