My Fedora Core 2 computer has two NIC cards.
How to assign different IP addresses to them (eth0 and eth1) dynamically by dhcp?

My dhcpd.conf is:
ddns-update-style interim;

subnet 192.168.0.0 netmask 255.255.255.0 {
option routers 192.168.0.1;
range 192.168.0.2 192.168.0.254;
}

subnet 192.168.3.0 netmask 255.255.255.0 {
option routers 192.168.3.1;
range 192.168.3.2 192.168.3.254;
}

ifcfg-eth0 and ifcfg-eth1 are similar.
/etc/sysconfig/network-scripts/ifcfg-eth1 is:
DEVICE=eth1
BOOTPROTO=dhcp
HWADDR=00:30:48:83:E9:11
ONBOOT=yes
TYPE=Ethernet
DHCP_HOSTNAME=rose
USERCTL=no
IPV6INIT=no
PEERDNS=no

you would presumably just use the mac address in the dhcpd.conf to assign the addresses per hardware item.

I want to assign two different subnet addresses.
e.g.
eth0 get 192.168.0.2
eth1 get 192.168.3.2

/etc/dhcpd.conf is now:
ddns-update-style interim;

subnet 192.168.0.0 netmask 255.255.255.0 {
option routers 192.168.0.1;
range 192.168.0.2 192.168.0.254;
}

subnet 192.168.3.0 netmask 255.255.255.0 {
option routers 192.168.3.1;
range 192.168.3.2 192.168.3.254;
}


host rose {
hardware ethernet 00:30:48:83:E9:11;
fixed-address 192.168.3.2;
}


# /usr/sbin/dhcpd eth1
Internet Systems Consortium DHCP Server V3.0.1rc14
Copyright 2004 Internet Systems Consortium.
All rights reserved.
For info, please visit http://www.isc.org/sw/dhcp/
Wrote 0 deleted host decls to leases file.
Wrote 0 new dynamic host decls to leases file.
Wrote 4 leases to leases file.

No subnet declaration for eth1 (0.0.0.0).
** Ignoring requests on eth1. If this is not what
you want, please write a subnet declaration
in your dhcpd.conf file for the network segment
to which interface eth1 is attached. **

ok, what do you actually want to achieve... if YOU are the DHCP server, then don't use DHCP. you can't give yourself leases. or at least shouldn't. if you are not the DHCP server then you will be given a dhcp address suitable for the netwrok that you are responding on. it's implicit that they will get the right ones as they are on different networks.

Yuo have posted the config file for a DHCP *server* but it sounds like you want to be a DHCP *client*. If you want your computer to automatically get the right addresses for two networks it is connected to, plug them in and enable DHCP (client) on the network cards.

If you want to make it give other systems on the networks addresses then set up a DHCP server using something similiar to your config file. Start dhcpd, the DHCP server daemon, with paramater for each network card (something like /sbin/dhcpd eth0 eth1) and then *statically set a manual IP address to each network interface.* If your system doesn't have a network interface with a static IP on that subnet, the DHCP server will not give out addresses in that range and in some cases will not even start.

I am sorry for the confusion, let me clarify:
I want to setup a Fedora core 2 dhcp server which has two NIC cards (eth0 & eth1). Any computers (e.g. computer A) connecting to eth0 will get IP addresses from 192.168.0.3 to 192.168.0.254; any computers (e.g. computer B) connecting to eth1 will get IP addresses from 192.168.3.3 to 192.168.3.254.
e.g.
eth0 get 192.168.0.2
eth1 get 192.168.3.2
computer A get 192.168.0.3 to 192.168.0.254
computer B get 192.168.3.3 to 192.168.3.254

well that's still as clear as mud really... but you would just assign a range the fits with the subnet on each eth interface. if a dhcp request is recieved on a client reaching the server from 192.168.3.x then it would be given one address from the 192.168.3.x pool.

To set a NIC's IP address from the command line it's ifconfig eth0 192.168.0.2 netmask 255.255.255.0 but to set it up permanantly either edit the startup script or use one of the graphical config tools in FC.