DHCP Server Configuration

Overview

A DHCP Dynamic Host Configuration Protocol Server is a network server that automatically provides and assigns IP addresses, default gateways and other network parameters to client devices. It relies on the standard protocol known as Dynamic Host Configuration Protocol or DHCP to respond to broadcast queries by clients.

DHCP Server Configuration for IPv4

Before configuring make sure that DHCP server is ready.

Topology

Figure 27. DHCP IPv4 topology

Configuration

DHCP IPv4 Client Interface

#configure terminal	Enter Configure mode.
(config)#interface xe1	Specify the interface (xe1) to be configured and enter the interface mode.
(config-if)#ip address dhcp	The client requests for the IP address to the server, once it receives the acknowledgment from the server, it assigns the IP address to the interface in which this command is enabled.
(config-if)#ip dhcp client request dns-nameserver	The client requests for the DNS name server.
(config-if)#ip dhcp client request ntp-server	The client requests for the NTP server .
(config-if)#ip dhcp client request host-name	The client requests for the Name of the client.
(config-if)#ip dhcp client request log-server	The client requests for the log server.
(config if)#exit	Exit interface mode.

DHCP IPv4 Server Interface

#configure terminal	Enter Configure mode.
(config)#interface xe2	Specify the interface (xe2) to be configured and enter the interface mode.
(config-if)#ip address 10.10.10.1/24	Configure the IP address to the server interface.
(config-if)#ip address dhcp	The client requests for the IP address to the server, once it receives the acknowledgment from the server, it assigns the IP address to the interface in which this command is enabled.
(config if)#exit	Exit interface mode.
(config)#commit	Commit the candidate configuration to the running configuration.

DHCP IPv4 Server Feature

#configure terminal	Enter Configure mode.
(config)#ip vrf vrf1	Configure IP VRF Virtual Routing and Forwarding name.
(config-vrf)#ip dhcp server max-lease-time 100	Configure max lease time.
(config-vrf)#ip dhcp server default-lease-time 100	Configure default lease time.
(config-vrf)#ip dhcp server pool test	Configure DHCP server pool name.
(dhcp-config)#network 3.3.3.0 netmask 255.255.255.0	Configure network and netmask.
(dhcp-config)#address range low-address 3.3.3.1 high-address 3.3.3.4	Configure address IPv4 range.
(dhcp-config)#routers 3.3.3.1	IPv4 DHCP Server option to provide router details to a DHCP client A DHCP client is a hardware device or software that uses DHCP to get the network configuration information from a DHCP Server.     VRF: VRF creates a logically isolated routing table within a single physical network device. Each VRF instance works as an independent routing instance that enables separate network traffic, maintains different routing tables, and provides network isolation..
(dhcp-config)#boot-file test	Configure boot-file name.
(dhcp-config)#host-name dhcp-server	Configure host name.
(dhcp-config)#ntp-server 4.4.4.5	Configure NTP server.
(dhcp-config)#log-server 5.5.5.6	Configure log server.
(dhcp-config)#dns-server 5.5.5.5	Configure DNS server.
(dhcp-config)#tftp-server 5.5.5.6	Configure TFTP server.
(dhcp-config)#boot-file test	Configure boot-file name.

DHCP Server Configuration for IPv6

Before configuring make sure that DHCP server is ready.

Topology

Figure 28. DHCP IPv6 topology

Configuration

DHCP IPv6 Client Interface

#configure terminal	Enter Configure mode.
(config)#interface xe47	Specify the interface (xe47) to be configured and enter the interface mode.
(config-if)#ipv6 address dhcp	The client requests for the IPv6 address to the server, once it receives the acknowledgment from the server, it assigns the IP address to the interface in which this command is enabled.
(config-if)#ipv6 dhcp client request dns-nameserver	The client requests for the DNS name server.
(config-if)#ipv6 dhcp client request ntp-server	The client requests for the NTP server.
(config-if)#ipv6 dhcp client request domain-search	The client request for IPv6 domain search.
(config-if)#ipv6 dhcp client request vendor-specific-information	The client request for IPv6 vendor-specific-information.
(config-if)#ipv6 dhcp client request rapid-commit	The client request to enable rapid-commit.
(config if)#exit	Exit interface mode.
(config)#commit	Commit the candidate configuration to the running configuration.

DHCP IPv6 Server Interface

#configure terminal	Enter Configure mode.
(config)#interface xe2	Specify the interface (xe2) to be configured and enter the interface mode.
(config-if)#ipv6 address dhcp	The client requests for the IPv6 address to the server, once it receives the acknowledgment from the server, it assigns the IP address to the interface in which this command is enabled.
(config-if)#ipv6 address 2001::1/64	Configure the IPv6 address to the server interface.
(config if)#ipv6 dhcp server	Configure an interface as a DHCP server starting interface.
(config if)#exit	Exit interface mode.
(config)#commit	Commit the candidate configuration to the running configuration.

DHCP IPv6 Server Feature

#configure terminal	Enter Configure mode
(config)#ip vrf vrf1	Configure IP VRF name
(config-vrf)#ipv6 dhcp server preference	Configure IPv6 DHCP server preference
(config-vrf)#ipv6 dhcp server rapid-commit	Configure IPv6 DHCP server rapid-commit
(config-vrf)#ipv6 dhcp server pool test	Configure IPv6 DHCP server pool name
(dhcp6-config)#network 2001:: netmask 64	Configure IPv6 network and netmask
(dhcp6-config)#address range low-address 2001::1 high-address 2001::124	Configure IPv6 address range
(dhcp6-config)#vendor-options 00:00:09:bf:63	Configure IPv6 vendor option
(dhcp6-config)#ntp-server 4001::1	Configure IPv6 NTP server
(dhcp6-config)#dns-server 3001::1	Configure IPv6 DNS server
(dhcp-config)#log-server 5.5.5.6	Configure log server
(dhcp6-config)#domain-name abcd	Configure domain name
(dhcp-config)#tftp-server 5.5.5.6	Configure TFTP server
(dhcp-config)#boot-file test	Configure boot-file name

Validation

Client

Server