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VLAN

A Broadcast domain.

Mac address table

Basicly a mac address table just with an extra colum for vlan id's

VLAN IDs

  • Normal VLAN ID range
  • 1 - 1005
  • 1 is the default VLAN
  • 1002 - 1005 are reserved
    • For legacy protocols
  • Stored in flash:/vlan.dat
  • Extended VLAN ID range
  • 1006 - 4096
  • Stored in running-config

Configuring VLAN

Example

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10.0.0.10/24 ---(F0/1) [Switch] (F0/2)--- 172.16.0.10/24
                  (F0/3)|   |(F0/4)
    10.0.0.11/24--------|   |--------172.16.0.11/24
  • VLAN 10
  • 10.0.0.10
  • 10.0.0.11
  • VLAN 20
  • 172.16.0.10
  • 172.16.0.11

Config

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en
conf t
vlan 10
name LEFT

vlan 20
name RIGHT

exit
exit
show vlan

Add a port to VLAN 10

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do show int f0/1
int f0/1
switchport mode access
switchport access vlan10
show vlan

Add a port to VLAN 20

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do show int f0/2
int f0/2
switchport mode access
switchport access vlan20
show vlan
* VTP - Vlan Trunking Protocol * vtp mode transparent