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vlan(4) [netbsd man page]

VLAN(4) 						   BSD Kernel Interfaces Manual 						   VLAN(4)

NAME

     vlan -- IEEE 802.1Q Virtual LAN network device

SYNOPSIS

     pseudo-device vlan

DESCRIPTION

     The vlan interface provides support for IEEE 802.1Q Virtual Local Area Networks (VLAN).  This supports the trunking of more than one network
     on a single network interface.  This is particularly useful on routers or on hosts which must be connected to many different networks through
     a single physical interface.

     To use a vlan interface, the administrator must first create the interface and then specify the VID (VLAN identifier, the first 12 bits from
     a 16-bit integer which distinguishes each VLAN from any others) and physical interface associated with the VLAN.  This can be done by using
     the ifconfig(8) create, vlan, and vlanif subcommands from a shell command line or script.	From within a C program, use the ioctl(2) system
     call with the SIOCSIFCREATE and SIOCSIFVLAN arguments.

     To be compatible with other IEEE 802.1Q devices, the vlan interface supports a 1500 byte MTU, which means that the parent interface will have
     to handle packets that are 4 bytes larger than the original Ethernet standard.  Drivers supporting this increased MTU are:

     -	 drivers using the DP8390 core (such as ec(4), ne(4), we(4), and possibly others)
     -	 bge(4)
     -	 bnx(4)
     -	 ea(4)
     -	 eb(4)
     -	 epic(4)
     -	 etherip(4)
     -	 ex(4)
     -	 fxp(4)
     -	 gem(4)
     -	 hme(4)
     -	 le(4)
     -	 sip(4)
     -	 ste(4)
     -	 stge(4)
     -	 ti(4)
     -	 tl(4)
     -	 tlp(4)
     -	 vge(4)
     -	 vr(4)
     -	 wm(4)
     -	 xi(4)

     vlan can be used with devices not supporting the IEEE 802.1Q MTU, but then the MTU of the vlan interface will be 4 bytes too small and will
     not interoperate properly with other IEEE 802.1Q devices, unless the MTU of the other hosts on the VLAN are also lowered to match.

EXAMPLES

     The following will create interface vlan0 with VID six, on the Ethernet interface tlp0:

	   ifconfig vlan0 create
	   ifconfig vlan0 vlan 6 vlanif tlp0

     After this set up, IP addresses (and/or other protocols) can be assigned to the vlan0 interface.  All other hosts on the Ethernet connected
     to tlp0 which configure a VLAN and use VID six will see all traffic transmitted through vlan0.

     The same VLAN can be created at system startup time by placing the following in /etc/ifconfig.vlan0:

	   create
	   vlan 6 vlanif tlp0

SEE ALSO

     ifconfig(8)

HISTORY

     The vlan device first appeared in NetBSD 1.5.1, and was derived from a VLAN implementation that appeared in FreeBSD and OpenBSD.

BUGS

     The vlan interfaces do not currently inherit changes made to the physical interfaces' MTU.

BSD
								 December 16, 2010							       BSD

Check Out this Related Man Page

VCONFIG(8)						      System Manager's Manual							VCONFIG(8)

NAME

       vconfig - VLAN (802.1q) configuration program.

SYNOPSIS

       vconfig [lots of long options]

DESCRIPTION

       The  vconfig program allows you to create and remove vlan-devices on a vlan enabled kernel. Vlan-devices are virtual ethernet devices which
       represents the virtual lans on the physical lan.

OPTIONS

       add [interface-name] [vlan-id]
	      Creates a vlan-device on [interface-name]. The resulting vlan-device will be called according to the nameing convention set.

       rem [vlan-device]
	      Removes the named vlan-device.

       set_flag [vlan-device] 0 | 1
	      When 1, ethernet header reorders are turned on. Dumping the device will appear as a  common  ethernet  device  without  vlans.  When
	      0(default)  however,  ethernet  headers are not reordered, which results in vlan tagged packets when dumping the device. Usually the
	      default gives no problems, but some packet filtering programs might have problems with it.

       set_egress_map [vlan-device] [skb-priority] [vlan-qos]
	      This flags that outbound packets with a particular skb-priority should be tagged with the particular  vlan  priority  vlan-qos.  The
	      default vlan priority is 0.

       set_ingress_map [vlan-device] [skb-priority] [vlan-qos]
	      This  flags  that  inbound  packets  with the particular vlan priority vlan-qos should be queued with a particular skb-priority. The
	      default skb-priority is 0.

       set_name_type VLAN_PLUS_VID | VLAN_PLUS_VID_NO_PAD | DEV_PLUS_VID | DEV_PLUS_VID_NO_PAD
	      Sets the way vlan-device names are created. Use vconfig without arguments to see the different formats.

       NOTES  VLAN will use Broadcom's NICE interface when the network device supports it. This is necessary, since usually the hardware of  these
	      devices  already	removes the vlan tag from the ethernet packet. The set_flag option on vlan-devices created on such a physical net-
	      work device will be ignored.  Dumping the network-device will show only untagged(non-vlan) traffic,  and	dumping  the  vlan-devices
	      will only show traffic intended for that vlan, without the tags.

FILES

       /proc/net/vlan/config
       /proc/net/vlan/[vlan-device]

SEE ALSO

       ip(8), ifconfig(8)

AUTHORS

       This manual page was written by Ard van Breemen <ard@kwaak.net>
       The vlan patch is written by Ben Greear <greearb@candelatech.com>

																	VCONFIG(8)
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