NAME

       mpls - mpls manipulation module

SYNOPSIS

       tc ... action mpls { POP | PUSH | MODIFY | dec_ttl } [ CONTROL ]

       POP := pop protocol MPLS_PROTO

       PUSH  :=  push [ protocol MPLS_PROTO ]  [ tc MPLS_TC ]  [ ttl MPLS_TTL ]  [ bos MPLS_BOS ]
               label MPLS_LABEL

       MODIFY := modify [ label MPLS_LABEL ]  [ tc MPLS_TC ]  [ ttl MPLS_TTL ]

       CONTROL := { reclassify | pipe | drop | continue | pass | goto chain CHAIN_INDEX }

DESCRIPTION

       The mpls action performs mpls encapsulation or decapsulation on a packet, reflected by the
       operation modes POP, PUSH, MODIFY and DEC_TTL.  The POP mode requires the ethertype of the
       header that follows the MPLS header (e.g.  IPv4 or another MPLS). It will remove the outer
       MPLS  header  and  replace  the ethertype in the MAC header with that passed. The PUSH and
       MODIFY modes update the current MPLS  header  information  or  add  a  new  header.   PUSH
       requires  at  least  an  MPLS_LABEL.  DEC_TTL requires no arguments and simply subtracts 1
       from the MPLS header TTL field.

OPTIONS

       pop    Decapsulation mode. Requires the protocol of the next header.

       push   Encapsulation mode. Requires at least the label option.

       modify Replace mode. Existing MPLS tag is replaced.  label, tc, and ttl are all optional.

       dec_ttl
              Decrement the TTL field on the outer most MPLS header.

       label MPLS_LABEL
              Specify the MPLS LABEL for the outer MPLS header.  MPLS_LABEL is an unsigned  20bit
              integer,   the  format  is  detected  automatically  (e.g.  prefix  with  '0x'  for
              hexadecimal interpretation, etc.).

       protocol MPLS_PROTO
              Choose the protocol to use. For push  actions  this  must  be  mpls_uc  or  mpls_mc
              (mpls_uc  is  the  default).  For pop actions it should be the protocol of the next
              header.  This option cannot be used with modify.

       tc MPLS_TC
              Choose the TC value for the outer MPLS header. Decimal  number  in  range  of  0-7.
              Defaults to 0.

       ttl MPLS_TTL
              Choose  the  TTL  value for the outer MPLS header. Number in range of 0-255. A non-
              zero default value will be selected if this is not explicitly set.

       bos MPLS_BOS
              Manually configure the bottom of stack bit for an MPLS header push. The default  is
              for  TC  to  automatically  set  (or unset) the bit based on the next header of the
              packet.

       CONTROL
              How to continue after executing this action.

              reclassify
                     Restarts classification by jumping back to the first filter attached to this
                     action's parent.

              pipe   Continue with the next action, this is the default.

              drop   Packet will be dropped without running further actions.

              continue
                     Continue classification with next filter in line.

              pass   Return  to calling qdisc for packet processing. This ends the classification
                     process.

EXAMPLES

       The following example encapsulates incoming IP packets on eth0 into MPLS with a label  123
       and sends them out eth1:

              #tc qdisc add dev eth0 handle ffff: ingress
              #tc filter add dev eth0 protocol ip parent ffff: flower \
                   action mpls push protocol mpls_uc label 123  \
                   action mirred egress redirect dev eth1

       In  this example, incoming MPLS unicast packets on eth0 are decapsulated and to ip packets
       and output to eth1:

              #tc qdisc add dev eth0 handle ffff: ingress
              #tc filter add dev eth0 protocol mpls_uc parent ffff: flower \
                   action mpls pop protocol ipv4  \
                   action mirred egress redirect dev eth0

SEE ALSO

       tc(8)