The DHCP service automates assignment of IP addresses and configures the DNS server and gateway for computers on local networks using DHCP (Dynamic Host Configuration Protocol).
When the DHCP service receives an initial request from a client host, it assigns an available IP address from its address range. Upon subsequent requests by the same MAC address, the DHCP Server will attempt to reassign the same IP address. The only case in which it will not reassign the same IP address is when the number of DHCP clients exceeds the number of IP addresses
available, and the IP address has been assigned to a different host.
The DHCP service manages a range of IP addresses (e.g. 10.10.10.4 through 10.10.10.254) which can be assigned to hosts. Non-contiguous sets of IP addresses can be defined using exclusion ranges. Exclusion ranges, configured under the AdvANced tab, indicate which IP addresses within the previously
defined address range must not be assigned to hosts.
WINS uses a distributed database that is automatically updated with the names of computers currently available and the IP address assigned to each one. To use WINS, enter the IP address of the WINS server in the wiNS Server iP aDDreSS field. Hosts on the network must be configured to point to the
Default gateway for the location of their WINS server.
The DHCP service can also assign static leases to hosts on the network. Static leases are useful for managing “static” systems, such as print servers, mail servers or other hosts that need fixed configurations. Static leases are configured under the AdvANced tab.
To configure the DHCP server, navigate to Configure>Services>DHCP>Server and unselect the DiSable
checkbox. Both DHCPv4 and DHCPv6 are supported.
Changes to the DHCP service are applied when you click SAve.
DHCPv4
Table 3.12a: DHCPv4 Setup
Field Description
Disable Disable this DHCP IP address pool.
Type Select DHCPv4.
Description User-defined description of the IP address pool.
Beginning address First IP address of the pool’s range.
Ending address Last IP address of the pool’s range.
Netmask Subnet mask used to divide hosts into network groups.
Lease Duration Maximum length of time the assigned IP address may be used before renewal. A client must negotiate IP address renewal before the expiration of the lease, or quit using the IP address.
Options
Default Gateway Gateway (default route) given to DHCP clients. For hosts located behind a firewall (on protected or PSNs) this will be the IP address of the firewall’s corresponding interface.
Domain Name DNS domain name, typically that of the local network.
Name Server iP address IP address of a DNS server that will be issued to the requesting client. This can be any valid server: a local server, such as the built-in DNS Server, or a remote server, such as one located at an ISP. Up to three name servers can be defined.
WiNS Server iP address IP address of the WINS server that will be issued to the requesting client. Up to three WINS servers can be defined.
Network Time IP address of the network time server that will be issued to the requesting client. Up to three network time servers can be defined.
Advanced
MTU Maximum Transmission Unit. The MTU size determines the greatest packet size that can be transmitted by the DHCP service. A value of 0 means the field is ignored.
TFTP Server Enter the TFTP server for transferring data. Advanced
Static Leases
Disable Disables the selected row.
Host Name The host name to be used by the static lease.
iP address The desired IP address to be statically leased to the host.
MaC address The host’s MAC address.
Description A description of the host’s static lease. Exclusion Ranges
Exclusion Ranges Define up to five address ranges to exclude from each DHCP range. To exclude a single IP address, enter it in both the beginning and ending address fields.
DHCPv6
The IPv6 DHCP Server requires that the firewall be configured for prefix advertisement. For more infor- mation, see the Configuring IPv6 Guide.
To configure the DHCP server, navigate to Configure>Services>DHCP>Server and choose DHCPv6 in the tyPe
pulldown.
Figure 3.10b: DHCPv6 Server Setup
Table 3.12b: DHCPv6 Setup
Field Description
Disable Disable this DHCP IP address pool.
Type Select DHCPv6.
Description User-defined description of the IP address pool.
Beginning address First IP address of the pool’s range.
Ending address Last IP address of the pool’s range.
Prefix Length Define the prefix length.
Lease Duration Maximum length of time the assigned IP address may be used before renewal. A client must negotiate IP address renewal before the expiration of the lease, or quit using the IP address.
Options
Domain Name DNS domain name, typically that of the local network.
Name Server iP address IP address of a DNS server that will be issued to the requesting client. This can be any valid server: a local server, such as the built-in DNS Server, or a remote server, such as one located at an ISP. Up to three name servers can be defined. Advanced
Static Leases
Disable Disables the selected row.
Host Name The host name to be used by the static lease.
iP address The desired IP address to be statically leased to the host.
Client DUiD Enter the client’s DHCP unique identifier.
Description A description of the host’s static lease. Exclusion Ranges
Exclusion Ranges Define up to five address ranges to exclude from each DHCP range. To exclude a single IP address, enter it in both the beginning and ending address fields.