Overview
A switches is used to line up an local area network. A VLAN stands for a virtual local area network. By default, all
of the ports on a Cisco switch are a part of a similar default VLAN (VLAN1) and so a similar network. A VLAN may
be a network and a network may be a broadcast domain. If you configure numerous switch ports for separate
VLANs, then the devices on those ports can belong to separate VLANs and so, are going to be metameric into
separate broadcast domains and networks. this is often effectively like dividing a switch into multiple switches. this
is often value effective, as a result of rather than having multiple switches, every for a unique network, you’ll have
one switch organized for multiple VLANs and you’ll assign the ports thereon switch to belong to no matter VLAN
you would like the host to belong to.
VLAN Types
Data VLAN – It is a Virtual LAN carries only user data not management data, management data or voice data.
Default VLAN – On a Cisco switch the default VLAN is VLAN1. this suggests that by default, once a Cisco switch
boots up for the primary time all the ports ar mechanically appointed to the default VLAN, VLAN1. you can’t delete
or rename VLAN1 however you’ll assign the ports on the switch to a unique VLAN. it’s thought of best follow to
create all of the user ports on the switch belong to a unique default VLAN, one aside from VLAN1. during this
method, management data like CDP and stp (spanning tree protocol) that are by default carried on VLAN1 would
get on a separate Virtual LAN from user information.
Native VLAN – The native VLAN, if not expressly organized, can default to the default VLAN, (VLAN1). The
Native VLAN is configured for associate 802.1Q Trunk port. 802.1Q trunks carry traffic from multiple VLANs by
tagging the traffic with VLAN identifiers (Tagged Traffic) that identifies that packets are related to that VLANs, and
that they also can carry non VLAN traffic from bequest switches or non 802.1Q compliant switches (Untagged
Traffic). The switch can place unlabeled traffic on the Native VLAN by using a PVID identifier. Native VLAN traffic
isn’t labeled by the switch. it’s a best follow to configure the Native VLAN to diverge than VLAN1 and to configure
it on each ends of the trunk.
Management VLAN – The management VLAN is any VLAN you configure to permit a host to attach to the switch
and remotely manage it. The management VLAN can ought to be organized with associate IP address and subnet
mask to permit a manager to attach to the switch by either a web interface (HTTP), Telnet, SSH, or SNMP.
Virtual LAN ID Ranges
Normal range
1 to 1005
1 (default), created by default, can’t be deleted
1002-1005 (Token Ring and FDDI default), created by default and can’t be deleted
Stored within the VLAN.dat get in flash memory
Extended range
1006 – 4094
Extended range used by ISPs
Stored in Running-Config
Trunks – If you have got a switch that has ports diversely configured on four totally different VLANs, then that
switch has four totally different networks thereon. once you connect that switch to a router or to a different switch
you may would like four ethernet connections or links, one for every network. A additional value effective way to
connect a switch with multiple VLANs to a router or switch would be to configure a Trunk. A Trunk may be a
special quite port configuration that permits multiple VLANs to travel over one link. this fashion multiple networks
will travel over one trunk rather than wasting valuable ports to attach from switch to change or switch to router. A
Cisco trunk by default uses the 802.1Q protocol. The 802.1Q protocol places and strips VLAN tags on packets to
spot that VLAN they belong to.
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