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CCNP SWITCH Portable Command Guide: Implementing Inter-VLAN Routing

This chapter provides information and commands concerning the following topics:

Inter-VLAN communication

  • Inter-VLAN communication using an external router: router-on-a-stick
  • Inter-VLAN communication tips
  • Inter-VLAN communication on a multilayer switch through a switch virtual interface
    • - Removing L2 switchport capability of a switch port
    • - Configuring SVI Autostate
    • - Configuring a Layer 3 EtherChannel
    • - Configuring inter-VLAN communication
  • Configuration example: inter-VLAN communication

DHCP

  • Configuring DHCP server on a Router or Layer 3 Switch
  • Verifying and troubleshooting DHCP configuration
  • Configuring a DHCP helper address
  • DHCP client on a Cisco IOS Software Ethernet interface
  • Configuration example: DHCP

CEF

  • Configuring Cisco Express Forwarding (CEF)
  • Verifying CEF
  • Troubleshooting CEF

Inter-VLAN Communication Using an External Router: Router-on-a-Stick

Router(config)#interface fastethernet 0/0

Moves to interface configuration mode.

Router(config-if)#duplex full

Sets interface to full duplex.

Router(config-if)#no shutdown

Enables interface.

Router(config-if)#interface fastethernet 0/0.1

Creates subinterface 0/0.1 and moves to subinterface configuration mode.

Router(config-subif)#description Management VLAN 1

(Optional) Sets locally significant descriptor of the subinterface.

Router(config-subif)#encapsulation dot1q 1 native

Assigns VLAN 1 to this subinterface. VLAN 1 is the native VLAN. This subinterface uses the 802.1Q trunking protocol.

Router(config-subif)#ip address 192.168.1.1 255.255.255.0

Assigns IP address and netmask.

Router(config-subif)#interface fastethernet 0/0.10

Creates subinterface 0/0.10 and moves to subinterface configuration mode.

Router(config-subif)#description Accounting VLAN 10

(Optional) Sets locally significant descriptor of the subinterface.

Router(config-subif)#encapsulation dot1q 10

Assigns VLAN 10 to this subinterface. This subinterface uses the 802.1Q trunking protocol.

Router(config-subif)#ip address 192.168.10.1 255.255.255.0

Assigns IP address and netmask.

Router(config-subif)#exit

Returns to interface configuration mode.

Router(config-if)#exit

Returns to global configuration mode.

Router(config)#

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