native vlan

[carl_townshend]

when I have a switch my new, is vlan 1 classed as native by default, or do I have to tell it to be native, also soes native mean it doesnt tag the traffic ?

[Anand Narayana]

by default vlan 1 is the native vlan & u need not specify anything. also this vlan 1 interface is a management vlan for the switch, it cannot be deleted at all, because for setting up an ip address on the switch, it would be possible on a management interface which is by default vlan 1 on any switch(eg. cisco,nortel,3com etc...)

hope ur clear

[rajesh.rachuri]

I agree with ur statement because ur point is right that it is not possible to delete the Administrative VLAN. Today I cleared my doubt completetly by seeing ur this info. on this topic of Vlan.

[ankbhasi]

Hi Carl,

All switches by default native vlan is 1 on a trunk port and you do not need to tell it to be native.

But you have to configure a trunk port and once trunk is up and running fine native vlan on that trunk by default will be 1.

Yes native vlan traffic is send untagged on a trunk port.

HTH

Ankur

*Pls rate all helpfull post

[carl_townshend]

when you say vlan 1 is for management, does this mean that none of the ports need to be in vlan 1 as you can still get to the switch via the trunk which allows vlan 1 ?

[ankbhasi]

Hi Carl,

If any ports should be in vlan 1 or not it depends on your network requirement but if vlan 1 is allowed on trunk you can still get to the switch vai trunk which allows it no matter any physical port is assigned to vlan 1 or not.

HTH

Ankur

[smothuku]

Hi Carl ,

When you use an IEEE 802.1Q trunk port, all frames are tagged except those on the VLAN configured as the "native VLAN" for the port. Frames on the native VLAN are always transmitted untagged and are normally received untagged.

[carl_townshend]

so what is the benifit of this untagged traffic ?

[smothuku]

Hi Carl,

The native Vlan is implicitly used for

all the untagged traffic received on an 802.1Q capable port.

This capability is desirable because it allows 802.1Q capable ports to talk to old 802.3 ports directly by sending and receiving untagged traffic.

[smothuku]

Hi Carl ,

Frames can be tagged or untagged. A tagged frame is a frame that contains a VLAN tag. An untagged frame does not have a VLAN tag, but will be tagged when it is received on a port. A tagged frame may have already been processed by an 802.1Q switch or originated at an endpoint capable of inserting a VLAN tag into a frame. A VLAN tag may or may not contain a VLAN ID (VID), but it will always contain priority information. End systems are allowed to transmit frames with only a priority in the VLAN tag. When switches transmit a tagged frame, the VLAN tag will always include a VID along with the priority.

Tagged and untagged frames are assigned VLAN membership and transmission priority differently:

Untagged Frame - VLAN Membership

When an untagged frame is received on a port, if a VLAN Classification rule exists for the frame's classification type, the frame will gain membership in the associated VLAN. If not, the frame will be assigned to the VLAN identified as the port's VLAN ID (PVID).

Untagged Frame - Priority Assignment

When an untagged frame is received on a port, if a Priority Classification rule exists for the frame's classification type, the frame will be assigned the associated priority. If not, the frame will be assigned the port's default priority.

Tagged Frame - VLAN Membership

If a tagged frame includes a VID (VLAN ID), it will gain membership in the VLAN indicated by the VID. If not, and a VLAN Classification rule exists for the frame's classification type, the frame will be put into the associated VLAN. If there is no VID or classification rule, the frame will be put in the VLAN associated with the port's VLAN ID (PVID).

Tagged Frame - Priority Assignment

When a tagged frame is received on a port, it is assigned the priority contained in the VLAN tag.

Hope it helps you.

[#11]

I have a question about this. I have a non-cisco wireless access point that supports 802.1Q trunking. It will support multiple SSIDs assigned to multiple VLANs. The only thing is, it has to be connected to a switchport supporting 802.1Q and be on VLAN 1. My question is, how do i specify that VLAN 1 frames are tagged on a particular trunk port.

The AP is a Netgear WG302 latest firmware and the switch is a Cat4510 Enhanced L-3 image.