Tested on 23 May 2003 on Red Hat9

dhcp-3.0PL1-23 (DHCPD)

Description

dhcpd - Dynamic Host Configuration Protocol Server

The Internet Software Consortium DHCP Server, dhcpd, implements the Dynamic Host Configuration Protocol (DHCP). DHCP allows hosts on a TCP/IP network to request and be assigned IP addresses, and also to discover information about the network to which they are attached.

Configure

Install DHCP from Red Hat CD

# rpm -ihv dhcp-3.0PL1-23.i386.rpm

Copy a configuration file

# cp /usr/share/doc/dhcp-3.0pl1/dhcpd.conf.sample /etc/dhcpd.conf

Edit /etc/dhcpd.conf

ddns-update-style interim;
ignore client-updates;

subnet 192.168.0.0 netmask 255.255.255.0 {

# --- default gateway
        option routers                  192.168.0.1;
        option subnet-mask              255.255.255.0;

        option nis-domain               "domain.org";
        option domain-name              "domain.org";
        option domain-name-servers      192.168.0.1;

# Eastern Standard Time GMT -05:00 = -5x60x60 = -18000
#        option time-offset              -18000; 
# Eastern Standard Time GMT +06:00 =  6x60x60 =  21600
        option time-offset              21600; 
       option ntp-servers              192.168.0.1;
       option netbios-name-servers     192.168.0.2;
# --- Selects point-to-point node (default is hybrid). Don't change this unless
#       option netbios-node-type 2;

        range dynamic-bootp 192.168.0.128 192.168.0.255;
        default-lease-time 21600;
        max-lease-time 43200;

        # we want the nameserver to appear at a fixed address
        host ns {
                next-server ns.domain.org;
                hardware ethernet 12:34:56:78:AB:CD;
                fixed-address 192.168.0.3;
        }
}

Start the service
```
# /etc/rc.d/init.d/dhcpd start
```
Run DHCPD as a service when it restarted. (ntsysv or redhat-config-services also ok)
```
# chkconfig dhcpd on
```

Setup client

Windows 95/98/Me

Run winipcfg.exe to check IP Address

Windows NT/2000

Open DOS Command Prompt and type ipconfig. example

Sample Description

ipconfig Show information

ipconfig /all Show detailed information

ipconfig /renew EL* renew all adapters

ipconfig /release *ELINK?21* release all matching adapters

Sample	Description
ipconfig	Show information
ipconfig /all	Show detailed information
ipconfig /renew EL*	renew all adapters
ipconfig /release ELINK?21	release all matching adapters

Red Hat Linux 8.0 and 9

Sample	Description
ifconfig	Show information
dhclient	Get IP Address
dhclient -r	Release
dhclient -1	Try once to get a lease

Old Red Hat Linux

Sample	Description
ifconfig	Show information
pump	Get IP Address
pump -k	End pump daemon and return IP Address to DHCP Server
pump -s	Show information

Showing leased list by PHP on the web

<html>
<head>
<title>DHCPD Leased List</title>
</head>
<body>
<h1>DHCPD Leased List</h1>
<?
$fileleases = "/var/lib/dhcp/dhcpd.leases";
$dl=file($fileleases);
$ln=0;
for ( $i = 0 ; $i <= sizeof($dl) ; $i++) {
	$item=chop(ltrim($dl[$i]));
	if ( substr($item, 0, 5) == "lease" ) {
		$ln++;
		$dhcplist[$ln]['ip']=substr($item, 6, strpos($item, " ", 7)-6);
		}
	elseif ( substr($item, 0, 1) != "}") {
		switch( substr($item,0,3)) {
			case "sta";
				$dhcplist[$ln]['sta'] = substr($item, 9, strrpos($item, ";") -9);
				break;
			case "end";
				$dhcplist[$ln]['end'] = substr($item, 7, strrpos($item, ";") -7);
				break;
			case "uid";
				$dhcplist[$ln]['uid'] = substr($item, 4, strrpos($item, ";") -4);
				break;
			case "har";
				$dhcplist[$ln]['har'] = substr($item, 9, strrpos($item, ";") -9);
				break;
			case "cli";
				$dhcplist[$ln]['cli'] = substr($item, 17, strrpos($item, ";") -18);
				break;
			case "aba";
				$dhcplist[$ln]['aba'] = TRUE;
				break;
			}
		}
	}
?>
<table width=100% border=1 align=center>
<tr><th>#</th><th>Hostname</th><th>IP</th><th>Hardware</td><th>Start</th><th>End</th></tr>
<?
$count=0;
for ($i=1; $i<=$ln; $i++) {
	if (!$dhcplist[$i]['aba']) {
		$count++;
		echo "<tr>";
		echo "<th>" . $count . "</th>";
		echo "<td>" . $dhcplist[$i]['cli'] . "</td>";
		echo "<td>" . $dhcplist[$i]['ip'] . "</td>";
		echo "<td>" . $dhcplist[$i]['har'] . "</td>";
		echo "<td>" . $dhcplist[$i]['sta'] . "</td>";
		echo "<td>" . $dhcplist[$i]['end'] . "</td>";
		echo "</tr>";
		}
	}
?>
</table>
<p align="right">Last Updated;
<? echo date("Y/m/d (D) H:i:s", filemtime($fileleases)); ?>
</p>
</body>
</html>

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