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.TH "VLAN manipulation action in tc" 8 "12 Jan 2015" "iproute2" "Linux"
.SH NAME
vlan - vlan manipulation module
.SH SYNOPSIS
.in +8
.ti -8
.BR tc " ... " "action vlan" " { " pop " | " pop_eth " |"
.IR PUSH " | " MODIFY " | " PUSH_ETH " } [ " CONTROL " ]"
.ti -8
.IR PUSH " := "
.BR push " [ " protocol
.IR VLANPROTO " ]"
.BR " [ " priority
.IR VLANPRIO " ] "
.BI id " VLANID"
.ti -8
.IR MODIFY " := "
.BR modify " [ " protocol
.IR VLANPROTO " ]"
.BR " [ " priority
.IR VLANPRIO " ] "
.BI id " VLANID"
.ti -8
.IR PUSH_ETH " := "
.B push_eth
.BI dst_mac " LLADDR " src_mac " LLADDR "
.ti -8
.IR CONTROL " := { "
.BR reclassify " | " pipe " | " drop " | " continue " | " pass " | " goto " " chain " " CHAIN_INDEX " }"
.SH DESCRIPTION
The
.B vlan
action allows one to perform 802.1Q en- or decapsulation on a packet, reflected by
the operation modes
.IR POP ", " PUSH " and " MODIFY .
The
.I POP
mode is simple, as no further information is required to just drop the
outer-most VLAN encapsulation. The
.IR PUSH " and " MODIFY
modes require at least a
.I VLANID
and allow one to optionally choose the
.I VLANPROTO
to use.
The
.B vlan
action can also be used to add or remove the base Ethernet header. The
.B pop_eth
mode, which takes no argument, is used to remove the base Ethernet header. All
existing VLANs must have been previously dropped. The opposite operation,
adding a base Ethernet header, is done with the
.B push_eth
mode. In that case, the packet must have no MAC header (stacking MAC headers is
not permitted). This mode is mostly useful when a previous action has
encapsulated the whole original frame behind a network header and one needs
to prepend an Ethernet header before forwarding the resulting packet.
.SH OPTIONS
.TP
.B pop
Decapsulation mode, no further arguments allowed.
.TP
.B push
Encapsulation mode. Requires at least
.B id
option.
.TP
.B modify
Replace mode. Existing 802.1Q tag is replaced. Requires at least
.B id
option.
.TP
.B pop_eth
Ethernet header decapsulation mode. Only works on a plain Ethernet header:
VLANs, if any, must be removed first.
.TP
.B push_eth
Ethernet header encapsulation mode. The Ethertype is automatically set
using the network header type. Chaining Ethernet headers is not allowed: the
packet must have no MAC header when using this mode. Requires the
.BR "dst_mac " and " src_mac " options.
.TP
.BI id " VLANID"
Specify the VLAN ID to encapsulate into.
.I VLANID
is an unsigned 16bit integer, the format is detected automatically (e.g. prefix
with
.RB ' 0x '
for hexadecimal interpretation, etc.).
.TP
.BI protocol " VLANPROTO"
Choose the VLAN protocol to use. At the time of writing, the kernel accepts only
.BR 802.1Q " or " 802.1ad .
.TP
.BI priority " VLANPRIO"
Choose the VLAN priority to use. Decimal number in range of 0-7.
.TP
.BI dst_mac " LLADDR"
Choose the destination MAC address to use.
.TP
.BI src_mac " LLADDR"
Choose the source MAC address to use.
.TP
.I CONTROL
How to continue after executing this action.
.RS
.TP
.B reclassify
Restarts classification by jumping back to the first filter attached to this
action's parent.
.TP
.B pipe
Continue with the next action, this is the default.
.TP
.B drop
Packet will be dropped without running further actions.
.TP
.B continue
Continue classification with next filter in line.
.TP
.B pass
Return to calling qdisc for packet processing. This ends the classification
process.
.RE
.SH EXAMPLES
The following example encapsulates incoming ICMP packets on eth0 from 10.0.0.2
into VLAN ID 123:
.RS
.EX
#tc qdisc add dev eth0 handle ffff: ingress
#tc filter add dev eth0 parent ffff: pref 11 protocol ip \\
u32 match ip protocol 1 0xff flowid 1:1 \\
match ip src 10.0.0.2 flowid 1:1 \\
action vlan push id 123
.EE
.RE
Here is an example of the
.B pop
function: Incoming VLAN packets on eth0 are decapsulated and the classification
process then restarted for the plain packet:
.RS
.EX
#tc qdisc add dev eth0 handle ffff: ingress
#tc filter add dev $ETH parent ffff: pref 1 protocol 802.1Q \\
u32 match u32 0 0 flowid 1:1 \\
action vlan pop reclassify
.EE
.RE
For an example of the
.BR pop_eth " and " push_eth " modes, see " tc-mpls (8).
.SH SEE ALSO
.BR tc "(8), " tc-mpls (8)
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