tc-ife(8) — Linux manual page


IFE action in tc(8)               Linux              IFE action in tc(8)

NAME         top

       IFE - encapsulate/decapsulate metadata

SYNOPSIS         top

       tc ...  action ife DIRECTION [ ACTION ] [ dst DMAC ] [ src SMAC ]
               [ type TYPE ] [ CONTROL ] [ index INDEX ]

       DIRECTION := { decode | encode }

       ACTION := { allow ATTR | use ATTR value }

       ATTR := { mark | prio | tcindex }

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

DESCRIPTION         top

       The ife action allows for a sending side to encapsulate arbitrary
       metadata, which is then decapsulated by the receiving end. The
       sender runs in encoding mode and the receiver in decode mode.
       Both sender and receiver must specify the same ethertype. In the
       future, a registered ethertype may be available as a default.

OPTIONS         top

       decode For the receiving side; decode the metadata if the packet

       encode For the sending side. Encode the specified metadata if the
              packet matches.

       allow  Encode direction only. Allows encoding specified metadata.

       use    Encode direction only. Enforce static encoding of
              specified metadata.

       mark [ u32_value ] The value to set for the skb mark. The u32
              value is required only when use is specified. If mark
              value is zero, it will not be encoded, instead
              "overlimits" statistics increment and CONTROL action is

       prio [ u32_value ] The value to set for priority in the skb
              structure. The u32 value is required only when use is

       tcindex [
              u16_value ] Value to set for the traffic control index in
              the skb structure. The u16 value is required only when use
              is specified.

       dmac DMAC
       smac SMAC
              Optional six byte destination or source MAC address to

       type TYPE
              Optional 16-bit ethertype to encode. If not specified
              value of 0xED3E will be used.

              Action to take following an encode/decode.

       index INDEX
              Assign a unique ID to this action instead of letting the
              kernel choose one automatically.  INDEX is a 32bit
              unsigned integer greater than zero.

EXAMPLES         top

       On the receiving side, match packets with ethertype 0xdead and
       restart classification so that it will match ICMP on the next
       rule, at prio 3:
              # tc qdisc add dev eth0 handle ffff: ingress
              # tc filter add dev eth0 parent ffff: prio 2 protocol 0xdead \
                   u32 match u32 0 0 flowid 1:1 \
                   action ife decode reclassify
              # tc filter add dev eth0 parent ffff: prio 3 protocol ip \
                   u32 match ip protocol 0xff flowid 1:1 \
                   action continue

       Match with skb mark of 17:

              # tc filter add dev eth0 parent ffff: prio 4 protocol ip \
                   handle 0x11 fw flowid 1:1 \
                   action ok

       Configure the sending side to encode for the filters above. Use a
       destination IP address of, then tag with skb
       mark of decimal 17. Encode the packaet with ethertype 0xdead, add
       skb->mark to whitelist of metadatum to send, and rewrite the
       destination MAC address to 02:15:15:15:15:15.

              # tc qdisc add dev eth0 root handle 1: prio
              # tc filter add dev eth0 parent 1: protocol ip prio 10 u32 \
                   match ip dst \
                   match ip protocol 1 0xff \
                   flowid 1:2 \
                   action skbedit mark 17 \
                   action ife encode \
                   type 0xDEAD \
                   allow mark \
                   dst 02:15:15:15:15:15

SEE ALSO         top

       tc(8), tc-u32(8)

COLOPHON         top

       This page is part of the iproute2 (utilities for controlling
       TCP/IP networking and traffic) project.  Information about the
       project can be found at 
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       obtained from the project's upstream Git repository
       ⟨⟩ on
       2023-12-22.  (At that time, the date of the most recent commit
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iproute2                       22 Apr 2016           IFE action in tc(8)

Pages that refer to this page: tc-actions(8)