VLAN manipulation action in tc - Online Linux Manual Page

Section : 8
Updated : 12 Jan 2015
Source : iproute2
Note : Linux

NAME

vlan - vlan manipulation module

SYNOPSIS

...

action vlan

{

pop

pop_eth

PUSH

MODIFY

PUSH_ETH

}

[

CONTROL

]

PUSH

push

[

protocol

VLANPROTO

]

[

priority

VLANPRIO

]

VLANID

MODIFY

modify

[

protocol

VLANPROTO

]

[

priority

VLANPRIO

]

VLANID

PUSH_ETH

push_eth

dst_mac

LLADDR

src_mac

LLADDR

CONTROL

:= {

reclassify

pipe

drop

continue

pass

goto

chain

CHAIN_INDEX

}

DESCRIPTION

The vlan action allows one to perform 802.1Q en- or decapsulation on a packet, reflected by the operation modes POP

PUSH

and

MODIFY

. The POP mode is simple, as no further information is required to just drop the outer-most VLAN encapsulation. The PUSH

and

MODIFY modes require at least a VLANID and allow one to optionally choose the VLANPROTO to use. The vlan action can also be used to add or remove the base Ethernet header. The 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 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.

OPTIONS

pop

Decapsulation mode, no further arguments allowed.

push

Encapsulation mode. Requires at least id option.

modify

Replace mode. Existing 802.1Q tag is replaced. Requires at least id option.

pop_eth

Ethernet header decapsulation mode. Only works on a plain Ethernet header: VLANs, if any, must be removed first.

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 dst_mac

and

src_mac

options.

VLANID

Specify the VLAN ID to encapsulate into. VLANID is an unsigned 16bit integer, the format is detected automatically (e.g. prefix with

for hexadecimal interpretation, etc.).

protocol

VLANPROTO

Choose the VLAN protocol to use. At the time of writing, the kernel accepts only 802.1Q

802.1ad

priority

VLANPRIO

Choose the VLAN priority to use. Decimal number in range of 0-7.

dst_mac

LLADDR

Choose the destination MAC address to use.

src_mac

LLADDR

Choose the source MAC address to use.

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 ICMP packets on eth0 from 10.0.0.2 into VLAN ID 123:

#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

Here is an example of the pop function: Incoming VLAN packets on eth0 are decapsulated and the classification process then restarted for the plain packet:

#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

For an example of the pop_eth

and

push_eth

modes, see

tc-mpls

(8).