ip dhcp-server

This command enables the specified address of the DHCP relay server to be used on the specified interface or on all Layer 3 interfaces. It also provides support for the device to act as a DHCP server for Lync-enabled IP phones, by supporting DHCP Options 120 and 43. DHCP Option 120 enables SIP clients to discover a domain name system (DNS) FQDN (Fully-Qualified Domain Name) of a SIP server (SIP Server Discovery). For detailed information on DHCP Option 120, see RFC 3361. DHCP Option 43 enables devices to discover the Microsoft Lync Server Certificate Provisioning service. For detailed information on how to configure DHCP Option 120 and DHCP Option 43, see http://technet.microsoft.com/en-us/library/gg412828%28v=ocs.14%29.aspx.

Use the no form of this command to disable the address of the DHCP relay server on a specific interface or on all Layer 3 interfaces.

Not all the commands in this section have a no form. See the details in the commands syntax below. The no form for the ip dhcp-server <ip address> command is used to disable the DHCP relay server.

Syntax

# ip dhcp-server <ip address>{<interface> <interface ID>}
# ip dhcp-server all <interface> <interface ID>
 
# no ip dhcp-server <ip address>
 
# ip dhcp-server network <first ip address> <last ip address> <subnet mask>
# ip dhcp-server dns-server <dns ip address>
# ip dhcp-server netbios-name-server <wins ip address>
# ip dhcp-server lease <days> <hours> <minutes>
 
# ip dhcp-server boot-file-name <boot file name>
# no ip dhcp-server boot-file-name
 
# ip dhcp-server domain-name <domain name>
# no ip dhcp-server domain-name
 
# ip dhcp-server netbios-node-type <wins node type>
# no ip dhcp-server netbios-node-type
 
# ip dhcp-server ntp-server <ntp ip address>
# ip dhcp-server tftp-server <tftp ip address>
 
# ip dhcp-server tftp-server-name <tftp name>
# no ip dhcp-server tftp-server-name
 
# ip dhcp-server time-offset <time offset>
# no ip dhcp-server time-offset
 
# ip dhcp-server provide-host-name
# no ip dhcp-server provide-host-name
 
# ip dhcp-server sip-server <FQDN of SIP server – Option 120)
# ip dhcp-server lync-cert-provisioning <Microsoft Lync Server Certificate Provisioning service – Option 43> 
 
# ip dhcp-server option82

Command	Description
ip address	Specifies a valid IPv4 address. IP addresses should be expressed in dotted decimal notation (for example, 10.1.2.3). Specifies a valid IPv4 address for the DHCP relay server.
first ip address last ip address subnet mask	Specifies the address pool of the DHCP relay server (valid IPv4 address). IP addresses should be expressed in dotted decimal notation.
dns ip address	Specifies a valid IPv4 address for the dns server. IP addresses should be expressed in dotted decimal notation (for example, 10.1.2.3). This parameter is optional.
wins ip address	Specifies a valid IPv4 address for wins server. IP addresses should be expressed in dotted decimal notation (for example, 10.1.2.3). This parameter is optional.
days hours minutes	Specifies the number of days and/or hours and/or minutes for server leases. This parameter is optional (default is 1 hour).
boot file name	Specifies the name of the configuration file that the DHCP client should download from the TFTP server. This parameter is optional. (BOOTP / DHCP Option 67).
domain name	Specifies the domain name that client should use when resolving hostnames via DNS. This parameter is optional. (BOOTP / DHCP Option 15).
wins node type	Specifies the NetBIOS (WINS) node type (i.e. 1 = B-node, 2 = P-node, 4 = M-node, 8 = H-node). This parameter is optional. (BOOTP / DHCP Option 46).
ntp ip address	Specifies a valid IPv4 address for NTP server. IP addresses should be expressed in dotted decimal notation (for example, 10.1.2.3). This parameter is optional. (BOOTP / DHCP Option 42).
tftp ip address	Specifies a valid IPv4 address for TFTP server. IP addresses should be expressed in dotted decimal notation (for example, 10.1.2.3). This parameter is optional. (BOOTP / DHCP Option 150).
tftp name	Specifies a TFTP server name. This parameter is optional. (BOOTP / DHCP Option 66).
time offset	Specifies the offset of the client's subnet in seconds from Coordinated Universal Time (UTC). A positive offset indicates a location east of the zero meridian and a negative offset indicates a location west of the zero meridian. This parameter is optional. (BOOTP / DHCP Option 2).
tr069-acs-server-name	Supports sending a DHCP response with the URL of an Auto-Configuration Server (ACS) in reply to a DHCP request received from a client with the "dslforum.org" string in the Vendor Class Identifier (DHCP option 60). The device sends the URL in the Vendor Specific Information (DHCP option 43). This is applicable when the device is configured as a DHCP server and is used for TR-069 provisioning. Note: This command is applicable only to data-router functionality.
option82	Enables support for DHCP Option 82. This option is received from a DHCP relay agent that forwards client-originated DHCP packets to the device (acting as a DHCP server). When enabled, the device simply "echos" the information of Option 82 back to the DHCP client. The feature is enabled for the interface on which the DHCPv4 server is configured.

Interface Type (ifname)		Interface ID
gigabitethernet	GigabitEthernet interface slot and port (VLAN ID is optional)	[SLOT/PORT.VLANID]
cellular	Cellular interface ID	0/0
gre	Tunnel GRE ID	[1-255]
ipip	Tunnel IPIP ID	[1-255]
l2tp	L2TP ID	[0-99]
pppoe	PPPoE interface ID	[1-3]
pptp	PPTP ID	[0-99]
vlan	Vlan ID	[1-3999]
loopback	Loopback ID	[1-5]
bvi	Bridge interface	[1-255]

Default

Related Commands

This command is also available from the interface configuration sub-directory.

Command Mode

Privileged User

Example

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This example configures the DHCP relay address of 10.1.2.3 on VLAN 5:

# (config-data)# ip dhcp-server 10.1.2.3 vlan 5

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The following is an example of how to use tr069-acs-server-name parameter.

# (config-data)# interface vlan 10
# (conf-if-VLAN 10)# ip dhcp-server tr069-acs-server-name  srv_1