dadmin Command

Purpose

Used to query and modify the status of the DHCP server.

Syntax

dadmin [ -?] [ -v] [ -h Hostname] [ -n interval] [ -f] -d IpAddress | [ -x] -i | [ -x] -s | -t on|off|Value | -q IpAddress | -r IpAddress | -p IpAddress | -c Clientld

Description

The dadmin command lets the DHCP administrator query and modify the state of his DHCP servers' databases. It gives the administrator the ability to locally or remotely query the DHCP server for the status of an IP address, query for a pool of IP addresses, query for a client, delete an IP address mapping, refresh the server, and change the server's tracing level.

The dadmin command is backwards compatible with previous release DHCP servers to list their IP address status and refresh.

When querying for an IP address information, the dadmin command returns the IP address's status. And depending on the IP address's status, the dadmin command may return the lease duration, start lease time, last leased time, whether the server supports DNS A record updates for this IP address, and the client identifier which is mapped to this IP address.

When querying for a client information, the dadmin command returns the client's IP address and IP address status, the last time the client was given any IP address, the hostname and domain name used by the client, and whether the server supports DNS A record updates for this IP address.

When modifying the server tracing level, the dadmin command sets and returns the server tracing level in the form of a tracing mask. This mask represents a bitstring where each bit represents whether a specific log item is being traced by the server (see "DHCP Server Configuration File" in the online documentation). From least significant to most significant order, these log items are LOG_NONE, LOG_SYSERR, LOG_OBJERR, LOG_PROTOCOL and LOG_PROTERR (same value), LOG_WARN, AND LOG_CONFIG (same value), LOG_EVENT, and LOG_PARSEERR (same value), LOG_ACTION, LOG_INFM, LOG_ACNTING, LOG_STAT, LOG_TRACE, LOG_START, and LOG_RTRACE.
Note: LOG_START cannot be disabled. This implies a mask range from 0x0800 through 0x1FFF.

Flags

Item Description
-c Clientld Returns the status for a specific client that may be known to the DHCP server. Clientld represents the client identifier that a DHCP client used to identify itself, or the field can either be specified as hexidecimal characters only, or in the TYPE-STRING representation used by the DHCP server.
-d IpAddress Deletes the lease information associated with IP address IpAddress. As a result, the address will be moved to the FREE state and be available for binding once again.
-f To be used with the -d flag. The -f flag forces the deletion of the address without any prompting. Deletes the lease information associated with IP.
-h Hostname Used to specify the destination DHCP server. Hostname can either be a name or IP address.
-i Reinitializes the DHCP server. This flag signals the server to sync its databases and restarts by rereading the configuration file.
-n interval Displays server statistics, summaries, and any requested intervals.
-p IpAddress Returns the status of each address in a subnet. IpAddress is used to identify the subnet to a list.
-q IpAddress Returns the status of a specific IP address.
-r IpAddress Puts the IP address in the Free state.
-s Returns the status of each address in the DHCP server's configured pools.
-t on|off|Value Changes the tracing level of the DHCP server. Trace values are reported in a hexidecimal format representing the tracing mask in use on the server. Value can be specified as either a decimal or hexidecimal format. The keywords on and off enable or disable a single bit at a time in the tracing mask.
-v Executes the command in verbose mode.
-x Use Version 1 of the dadmin protocol. The -x flag is used to connect to previous release DHCP servers and is only valid for the -i and -s flags. Follow with 6 when connecting with DHCPv6 server.
-? Displays the usage syntax.

Exit Status

Item Description
0 Successful completion.
>0 An error occurred.

Security

To secure connections from the dadmin clients, the DHCP server only allows connections from the server itself or from remote machines that are included in the superuser's .rhosts file. To prevent ordinary users from modifying the DHCP server's address mappings, the administrator should ensure that the execution of the dadmin command is limited to the proper users on those machines that are allowed access.

Files

Item Description
/usr/sbin/dadmin Contains the dadmin command.