.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 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 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

.SH SEE ALSO

.BR tc (8)