Cisco Systems OL-6426-02 manual Configuring a LAN with Dhcp and VLANs, Vlan

C H A P T E R 5

Configuring a LAN with DHCP and VLANs

The Cisco 1800 series integrated services fixed-configuration routers support clients on both physical LANs and virtual LANs (VLANs). The routers can use the Dynamic Host Configuration Protocol (DHCP) to enable automatic assignment of IP configurations for nodes on these networks. Other interfaces and configurations of the VLANs are described in the “Switch Port Configurations” section on page 5-7.

1

2

3

4

Fast Ethernet LAN (with multiple networked devices)

Router and DHCP server—Cisco 1800 series integrated services router—connected to the Internet

VLAN 1

VLAN 2

DHCP

DHCP, which is described in RFC 2131, uses a client/server model for address allocation. As an administrator, you can configure your Cisco 1800 integrated services fixed-configuration router to act as a DHCP server, providing IP address assignment and other TCP/IP-oriented configuration information to your workstations. DHCP frees you from having to manually assign an IP address to each client.

When you configure a DHCP server, you must configure the server properties, policies, and DHCP options.

Note Whenever you change server properties, you must reload the server with the configuration data from the Network Registrar database.

VLANs

The Cisco 1800 series integrated services routers (fixed) support eight Fast Ethernet ports on which you can configure VLANs. See the “Switch Port Configurations” section on page 5-7for a description of the interfaces and features that can be configured on the switch ports and a link to a document containing the configuration procedures.

VLANs enable networks to be segmented and formed into logical groups of users, regardless of the user’s physical location or LAN connection.

Configuration Tasks

Perform the following tasks to configure this network scenario:

•Configure DHCP

Book Title

OL-xxxxx-xx 5-1