Configure DHCP Server General Parameters

Configure DHCP general parameters for the hosted DHCP Server to change default values or specify information to advertise on all subnets. Configure only the parameters that apply to your deployment.

About this task

It is not mandatory to configure all parameters at the global level. You can also configure many of these parameters for specific subnets or hosts.

Procedure

Enter Global Configuration mode:

enable

configure terminal
Configure the DHCP Server as an authoritative DHCP server:
ip dhcp-server authoritative
By default, this option is disabled.
Configure the global lease expiration:
ip dhcp-server lease-time <60-300000000>
Configure the following optional parameters:
1. Configure the DNS servers globally:
  ip dhcp-server domain-name-servers {A.B.C.D} [...]
2. Configure the NTP servers globally:
  ip dhcp-server ntp-servers {A.B.C.D} [...]
3. Configure the TFTP server globally:
  
  ip dhcp-server tftp server-ip {A.B.C.D}
  
  ip dhcp-server tftp server-name WORD<0-64>
  
  ip dhcp-server tftp boot-file-name WORD<0-128>
4. Configure a domain name globally:
  
  ip dhcp-server domain-name WORD<0-255>
5. Configure global NetBIOS values:
  
  ip dhcp-server netbios-name-server {A.B.C.D}
  
  ip dhcp-server netbios-node-type {0x1|0x2|0x4|0x8}

Variable Definitions

The following table defines parameters for the ip dhcp-server command.


Variable	Definition
domain-name `WORD<0-255>`	Assigns a domain name to the DHCP Server.
domain-name-servers `{A.B.C.D} [...]`	Specifies the IPv4 address of one or more DNS servers. You can assign a maximum of eight servers. With multiple servers, list each server address on the same command line with a space between each address entry.
lease-time `<60-300000000>`	Assigns the global lease timer in seconds. The host lease expires when the timer expires. The default is 86400. Note: The DHCP renewal process begins when a lease reaches 50% of the remaining expiration timer. The client unicasts a renewal request to DHCP Server, which checks its database before confirming the renewal.
netbios-name-server `{A.B.C.D}`	Specifies the IPv4 address of the NetBIOS server.
netbios-node-type `{0x1\|0x2\|0x4\|0x8}`	Specifies the node type of the NetBIOS server. Enter one of the following values according to which value fits your deployment: `0x1`—B node `0x2`—P-node `0x4`—M-node `0x8`—H-node The default setting is `0x0` (unconfigured).
ntp-servers `{A.B.C.D} […]`	Specifies the IPv4 address of one or more NTP servers. You can assign a maximum of eight servers. With multiple servers, list each server address on the same command line with a space between each address entry.
tftp server-ip `{A.B.C.D}`	Specifies the IP address of the global TFTP server for DHCP Server. You must assign an IP address to the server before you can assign other TFTP settings such as a server name and boot image file.
tftp server-name `WORD<0-64>`	Specifies the server name of the global TFTP server for DHCP Server.
tftp boot-file name `WORD<0-128>`	Specifies the file name of the global TFTP boot image file for DHCP Server