Virtual LAN Számítógép hálózatok gyakorlata ÓBUDAI EGYETEM 2011 TAVASZI FÉLÉV 9. LABORGYAKORLAT PRÉM DÁNIEL

Virtual Local Area Network VLAN ≠ WLAN Virtual LAN (logically related network) broadcast domain inside the switch VLANs are stored in the VTP (VLAN trunking protocol) databases Configurable parameters of VLANs: name, type, state Some VLANs have a distinguished task, others can be used as arbitrarily (e.g.: 1 = management vlan) Cisco VLAN ranges – normal range: (configurable from 2) – extended range:

Virtual Local Area Network Machines in the same VLAN see each other as if they were in a normal LAN. Machines in separate VLANs don’t see traffic of the other VLAN (not even when they are connected to neighbouring ports on the same switch – 2nd layer) Separate VLANs can only communicate if there is routing between them (same as in normal LANs) – 3rd layer VLANs need configurating on switches and routers as well

VLAN Trunking Makes it possible to multiplex the traffic of more than one logical networks on one cable VLANID is used to separate the traffic Connection types: – Access:1 VLAN traffic – Trunk:Multiple VLANs batched (dot1Q -> IEEE 802.1q standard)

VLAN configuration in routers Router(config)# interface FastEthernet X/Y Router(config-if)# no shutdown Router(config-if)# exit Router(config)# interface FastEthernet X/Y.Z Router(config-subif)# encapsulation dot1Q [VLAN] Router(config-subif)# ip address [IP addr.] [subnet mask] Router(config-subif)# no shutdown Router(config-subif)# exit Where: – X,Y: Interface ID – Z:Sub interface ID (usually the VLANID) – [VLAN]:The VLAN ID

VLAN configuration on Swiches Switch> enable Switch# configure terminal Switch(config)# vlan [VLAN] Switch(config-vlan)# name [VLAN_NAME] Switch(config-vlan)# exit Where: – [VLAN]:is the VLAN ID – [VLAN_NAME] is the friendly name of the VLAN

VLAN configuration on Swiches //one interface Switch(config)# interface FastEthernet X/Y //interface range Switch(config)# interface range FastEthernet X/Y-Z Switch(config-if-range)# switchport access vlan [VLAN] Switch(config-if-range)# no shutdown Switch(config-if-range)# exit Where: – X,Y: ID of the first interface – Z:ID of the last interface – [VLAN]:The VLAN ID

VLAN configuration on Swiches //one interface Switch(config)# interface FastEthernet X/Y // interface range Switch(config)# interface range FastEthernet X/Y-Z Switch(config-if-range)# switchport mode trunk Switch(config-if-range)# switchport trunk allowed vlan add [VLAN 1] Switch(config-if-range)# switchport trunk allowed vlan add [VLAN 2] Switch(config-if-range)# switchport trunk allowed vlan add [VLAN N] Where: – X,Y: ID of the first interface – Z:ID of the last interface – [VLAN]:The VLAN ID