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NAME | SYNOPSIS | DESCRIPTION | OPTIONS | EXAMPLES | SEE ALSO | COLOPHON |
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IFE action in tc(8) Linux IFE action in tc(8)
IFE - encapsulate/decapsulate metadata
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 }
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.
decode For the receiving side; decode the metadata if the packet
matches.
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 taken.
prio [ u32_value ] The value to set for priority in the skb
structure. The u32 value is required only when use is
specified.
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
encode.
type TYPE
Optional 16-bit ethertype to encode. If not specified value
of 0xED3E will be used.
CONTROL
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.
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 192.168.122.237/24, then tag with skb
mark of decimal 17. Encode the packet with ethertype 0xdead, add
skb->mark to allowed list of meta datum 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 192.168.122.237/24 \
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
tc(8), tc-u32(8)
This page is part of the iproute2 (utilities for controlling
TCP/IP networking and traffic) project. Information about the
project can be found at
⟨http://www.linuxfoundation.org/collaborate/workgroups/networking/iproute2⟩.
If you have a bug report for this manual page, send it to
netdev@vger.kernel.org, shemminger@osdl.org. This page was
obtained from the project's upstream Git repository
⟨https://git.kernel.org/pub/scm/network/iproute2/iproute2.git⟩ on
2025-08-11. (At that time, the date of the most recent commit
that was found in the repository was 2025-08-08.) If you discover
any rendering problems in this HTML version of the page, or you
believe there is a better or more up-to-date source for the page,
or you have corrections or improvements to the information in this
COLOPHON (which is not part of the original manual page), send a
mail to man-pages@man7.org
iproute2 22 Apr 2016 IFE action in tc(8)
Pages that refer to this page: tc-actions(8)
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HTML rendering created 2025-09-06 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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