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Cisco Secure Router 520 Series Software Configuration Guide
OL-14210-01
Chapter 5 Configuring a LAN with DHCP and VLANs
Configure DHCP
Note Whenever you change server properties, you must reload the server with the configuration data from the
Network Registrar database.
VLANs
The Cisco Secure Router 520 Series routers support four Fast Ethernet ports on which you can configure
VLANs.
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
• Configure VLANs
Note The procedures in this chapter assume you have already configured basic router features as well as
PPPoE or PPPoA with NAT. If you have not performed these configurations tasks, see Chapter 1, “Basic
Router Configuration,” Chapter 3, “Configuring PPP over Ethernet with NAT,” and Chapter 4,
“Configuring PPP over ATM with NAT” as appropriate for your router.
Configure DHCP
Perform these steps to configure your router for DHCP operation, beginning in global configuration
mode:
Command Purpose
Step 1 ip domain name name
Example:
Router(config)# ip domain name smallbiz.com
Router(config)#
Identifies the default domain that the router uses to
complete unqualified hostnames (names without a
dotted-decimal domain name).
Step 2 ip name-server server-address1
[server-address2...server-address6]
Example:
Router(config)# ip name-server 192.168.11.12
Router(config)#
Specifies the address of one or more Domain
Name System (DNS) servers to use for name and
address resolution.
Step 3 ip dhcp excluded-address low-address
[high-address]
Example:
Router(config)# ip dhcp excluded-address
192.168.9.0
Specifies IP addresses that the DHCP server
should not assign to DHCP clients. In this
example, we are excluding the router address.