network jargon buster

[rocketpcguy]

i was trying to set up a dhcpd server for learning, and couldn't get a working dhcpd.conf file. i really don't understand what the options mean. these are simple stuff i see all the time but don't know the meaning.

my address is 192.168.0.1. i want to give IPs from 192.168.0.2 to 192.168.0.9

what does:
-netmask
-lease-time
-subnet
-broadcast-address
-dynamic-bootp
mean?

what should my subnet x.x.x.x netmask x.x.x.x {} be?

[happybunny]

netmask = 255.255.255.0
subnet = 192.168.0.0
lease-time = however long you want clients to keep that IP in seconds
broadcast = 192.168.0.255
dynamic-bootp = i don't htink you need this

[psi42]

Here's my dhcpd.conf ...


root@nargothrond:~# cat /etc/dhcpd.conf
# dhcpd.conf
#
# Configuration file for ISC dhcpd (see 'man dhcpd.conf')
#

default-lease-time 600;
max-lease-time 7200;
ddns-update-style none;
option subnet-mask 255.255.255.0;
option broadcast-address 10.0.0.255;
option routers 10.0.0.1;
option domain-name-servers 10.0.0.2;
option domain-name "localdomain";
option root-path "10.0.0.2:/share/ltsp/i386";
option log-servers 10.0.0.3;

subnet 10.0.0.0 netmask 255.255.255.0 {
range 10.0.0.201 10.0.0.254;
}

group {
use-host-decl-names on;

host terminal-101 {
hardware ethernet 00:90:27:A0:65:53;
fixed-address 10.0.0.101;
filename "/2.4.26-ltsp-1/pxelinux.0";
}
host terminal-102 {
hardware ethernet 00:60:B0:CD:C5:C1;
fixed-address 10.0.0.102;
filename "/2.4.26-ltsp-1/pxelinux.0";
}

}



It's got some LTSP stuff you won't need, but at least it will help you get going.

Just in case you haven't already read it, here is the DHCP mini-howto (http://www.tldp.org/HOWTO/DHCP/index.html).

:)

~psi42

[rocketpcguy]

thanks, but i read many of dhcp.conf files. i just want to know the meaning of those words, not suggested values. how did you know you had to type those values and what do they do?

-netmask
-lease-time
-subnet
-broadcast-address

any other important stuff for dhcp

[happybunny]

here are a couple of links:

http://www.yale.edu/pclt/COMM/TCPIP.HTM

http://www3.mwc.edu/~jhaynes/tcpip.htm


The netmask tells the system what part of your IP is the host (client) IP and which part defines the network. This helps it route traffic to other places.

the lease-time is how long the clients get to keep the IP DHCP gave them before asking for another IP.

Subnet defines the network number...the system needs to know which network it is plugged into to determine where to send traffic.

Broadcast address tells the system what IP to use to send a message to everyone on your subnet.