Cisco 850 Series, Configuration Manual, Page: 59 / 196

C H A P T E R
5-1
Cisco 850 Series and Cisco 870 Series Access Routers Software Configuration Guide
OL-5332-01
5
Configuring a LAN with DHCP and VLANs
The Cisco 870 series 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.
Figure 5-1 shows a typical deployment scenario with two physical LANs connected by the router and
two VLANs.
Figure 5-1 Physical and Virtual LANs with DHCP Configured on the Cisco Router
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1
2
3
4
1 Fast Ethernet LAN (with multiple networked devices)
2
Router and DHCP server—Cisco 870 series access router—connected to the Internet
3 VLAN 1
4 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 800 series 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.