System Administration Guide: IP Services

Customizing Performance Options for the DHCP Server

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

Table 15–3 Options Affecting DHCP Server Performance

Server Option 

Description 

Keyword 

Maximum number of BOOTP relay agent hops 

If a request has traveled through more than a given number of BOOTP relay agents, the request is dropped. The default maximum number of relay agent hops is four. This number is likely to be sufficient for most networks. A network might need more than four hops if DHCP requests pass through several BOOTP relay agents before reaching a DHCP server.

RELAY_HOPS=integer

Detect duplicate addresses 

By default, the server pings an IP address before offering the address to a client. A lack of response to the ping verifies that the address is not already in use. You can disable this feature to decrease the time that the server takes to make an offer. However, disabling the feature creates the risk of having duplicate IP addresses in use.

ICMP_VERIFY=TRUE/FALSE

Reload dhcptab automatically at specified intervals

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

RESCAN_INTERVAL=min

Cache offers of IP addresses for specified intervals 

After a server offers an IP address to a client, the offer is cached. While the offer is cached, 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 might need to increase the offer time.

OFFER_CACHE_TIMEOUT=sec

The following procedures describe how to change these options.