System Administration Guide: IP Services

Customizing DHCP Service Performance Options

You can change options that affect the performance of the DHCP service. These options are described in the following table.

Table 10–1 Options Affecting DHCP Server Performance

Server Option 

Description 

Key in /etc/inet/dhcpsvc.conf

Number of BOOTP relay agent hops 

If a request has traveled through more than a given number of BOOTP relay agents, it is dropped. The default maximum number of relay agent hops is 4, and it is not likely that this number will be surpassed unless your network is set up to pass requests through several BOOTP relay agents before they reach a DHCP server.

RELAY_HOPS=integer

Verification of IP address availability before making an offer 

By default, the server pings an IP address before offering it to a client to verify that it is not already in use. You can disable this feature to decrease the time it takes to make an offer, but this creates the risk of having duplicate IP addresses in use.

ICMP_VERIFY=TRUE/FALSE

Automatic reading of dhcptab at specified intervals

The server can be set to automatically read the dhcptab at the interval in minutes you specify. If your network configuration information does not change frequently, and you do not have multiple DHCP servers, it is not necessary to reload dhcptab automatically. Also note that DHCP Manager gives you the option to have the server reload dhcptab after you make a change to the data.

RESCAN_INTERVAL=min

Length of time to reserve an IP address that has been offered 

After a server offers an IP address to a client, it caches the offer, during which time the server does not offer the address again. You can change the number of seconds for which the offer is cached. The default is 10 seconds. On slow networks, you made need to increase the offer time.

OFFER_CACHE_TIMEOUT=sec

The following procedures describe how to change these options.