dhcpd 실행시 에러...........

실행시 다음과 같은 에러가 납니다.

[root@man /etc]# /usr/sbin/dhcpd stop
Internet Software Consortium DHCP Server 2.0
Copyright 1995, 1996, 1997, 1998, 1999 The Internet Software Consortium.
All rights reserved.

Please contribute if you find this software useful.
For info, please visit http://www.isc.org/dhcp-contrib.html

No subnet declaration for stop (0.0.0.0).
Please write a subnet declaration for the network segment to
which interface stop is attached.
exiting.
[root@man /etc]# /usr/sbin/dhcpd start
Internet Software Consortium DHCP Server 2.0
Copyright 1995, 1996, 1997, 1998, 1999 The Internet Software Consortium.
All rights reserved.

Please contribute if you find this software useful.
For info, please visit http://www.isc.org/dhcp-contrib.html

No subnet declaration for start (0.0.0.0).
Please write a subnet declaration for the network segment to
which interface start is attached.
exiting.
[root@man /etc]#

dhcpd.conf  내용입니다.

default-lease-time 600;
max-lease-time 7200;
option subnet-mask 255.255.255.0;
option broadcast-address 100.20.25.255;
option routers 100.20.25.1;
option domain-name-servers 168.126.63.1;

subnet 100.20.25.0 netmask 255.255.255.0{
        range 100.20.25.2 100.20.25.254;
}

dhcpd 2.0 을 쓰고 있습니다.

무엇이 문제인가요

가르쳐주세요