Talk:Virtual LAN

From Wikipedia, the free encyclopedia

Virtual Local Area Networks often referred to as VLANS are basically configured to seprate the broadcast domain in a switch. Now suppose there is a switch which has 100 ports out of which 40 belong to the marketing department of a company and rest 60 belong to sales. Now if marketing deparment never use data broadcasted by the sales department, then there is no use sending this data to them whenever a computer in the sales departement broadcasiioipoioits a piece of information and actually there is a disadvantage in doing so, it just encourages congestion in the network. So to solve this problem, the concept of VLANs was introduced. What Vlan will do is, it will divide a switch into two different broadcast domains, so even if somebody in sales does a broadcast, the particular data wont go to people in marketing, which is quite advantageous.

But its important to remember that by default all the ports in a new switch belong to Vlan 1, and this Vlan 1 can never be deleted or edited, but we can make more vlans and assign each port to a particular Vlan.This way the broadcast domain can be changed.

What is this "VLAN 1" (mentioned above and in a free-floating sentence on the main page). Nowhere has the concept of naming VLANs been introduced or any explanation of how they are named or numbered. It sounds to me like "VLAN 1" might be part of a particular scheme of VLANs, and so this information has little to do with VLANs in general. Is it a tip to do with a particular manufacturer's VLAN system? As a newcomer trying to read the main article this information seems out of place and irrelevant. Chard 17:49, 21 February 2007 (UTC)

I agree, and removed the following statement:

VLAN 1 is the default VLAN; it can never be deleted. All untagged traffic falls into this VLAN by default.

Whether VLAN 1 is default or can be deleted is up to the switch manufacturer. Untagged traffic uses whatever VLAN is defined as "native" when using 801.2q or when the port is on only one VLAN. --Rick Sidwell 01:18, 24 February 2007 (UTC)

Contents

[edit] taking vlan trunks into a host

is it possible if say a server is short on network cards to take a vlan trunk into the server and de-mulitplex it in software rather than connecting the server to a port on every vlan? Plugwash 04:53, 7 November 2005 (UTC)

Yes, if the server supports 802.1q. Keep in mind that "trunk" is not a standard term (although commonly used by Cisco and others), so look for 802.1q or vlan tags, not trunks in the server documentation. Some products use "trunk" to mean something entirely different, so this can get confusing.
this is certainly possible; on Linux you need a small program to configure the driver, though not all cards are physically able to do 802.1q IIRC. On Windoz it is similar - the network interface manufacturer will usually supply a utility to configure the driver. --Ali@gwc.org.uk 10:57, 13 November 2005 (UTC)
I just want to mention this article does a good job on describing what need to be done to make host vlan aware [1]


[edit] link to vlan faq just advertisment

Isnt the link to the FAQ just advertisment for ZeroShell? 213.3.23.38 22:23, 23 February 2007 (UTC)

ok

[edit] Single wire = hub not switch

"A VLAN consists of a network of computers that behave as if connected to the same wire"

Doesn't this incorrectly imply a VLAN is a single collision domain?

I suppose that could be a source of confusion- I've changed the language in question. --Clay Collier 02:19, 14 June 2007 (UTC)

[edit] Switches Have No Collision Domain?

I don't think the following statement is correct:
Section: Protocols and design

" When Ethernet switches made this a non-issue (because they have no collision domain) ... "

Switches do have a collision domain. Right?
-Manavkataria 14:40, 30 August 2007 (UTC)

No collision domain, but do have broadcast domain. 64.39.108.99 (talk) 01:00, 22 February 2008 (UTC)
They do have collision domains, one on each port. Pgallert (talk) 16:25, 29 April 2008 (UTC)
if the links are all full duplex (which most if not all switches support) then there are no collision domains. 02:17, 30 April 2008 (UTC)