Why use Vlan
- Reduce CPU
- Reduce security risk by reducing hosts that receive copies off frames that swiches flood
- Imporve security ofr hosts that send sensitive data by keeping host separate
- Flexibiolty
- Solve problem faster
- Reducce workload for STP
ISL and 802.1q – insert extra 4byte (12bit ) 802.1q vlan header into the original frames ethernet header. 2^12 = 4,096 4096 max vlans
Extended range VLAN ID – 1006-4096
VTP – VLAN Trunking Protocol
- Consistent VLAN configuration across all switches in the network
- VLAN trunking over mixed networks, such as ethernet to ATM LANE or even FDDI
- Accurate tracking and monitoring of VLANS
- Dynamic reporting of added VLANSs to a ll switches in the VTP domain
- Adding VLANs using Plug and Play.
- VTP server up to 1-1005 vlan id
- VTP transparent same as VTP off but sends VTP out interface
VTP
- Range (2-1001) (1002-1005 reservered)
- VTP synchronization every
- VTP sync to the highest rivision number in the VLAN configuraiton database
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VTP configuration must match
- The link between the switches be operating same VLAN trunk
- Two switch case sensitive VTP domain must match
- If configured case sensitive VTP password must match
- VTP sent every 5 minutes
- VTP mode, VTP domain, VTP password, VTP pruning, VTP version
- Vlan.dat file in flash