Hi community, this is my first post to this forum though I am referring it from long time back ....

I am having a DHCP server in my network with static ip 10.137.224.206 .. Nowdays it automatically gets a particular IP from assigned DHCP pool(IP: 10.137.225.21). I have checked the script files, removed that IP from DHCP pool too but still facing the same problem. whenever I do service restart it gets back to assigned static ip but after some time things went wrong ..

here is my dhcpd.conf file --

# dhcpd.conf
#
# Sample configuration file for ISC dhcpd
#

# option definitions common to all supported networks...
option domain-name "dcsp.local";
option domain-name-servers msadsp02.dcsp.local;

default-lease-time 600;
max-lease-time 7200;

# Use this to enble / disable dynamic dns updates globally.
ddns-update-style none;

# If this DHCP server is the official DHCP server for the local
# network, the authoritative directive should be uncommented.
authoritative;

# Use this to send dhcp log messages to a different log file (you also
# have to hack syslog.conf to complete the redirection).
log-facility local7;

# No service will be given on this subnet, but declaring it helps the
# DHCP server to understand the network topology.

subnet 10.137.224.0 netmask 255.255.240.0 {
}

# This is a very basic subnet declaration.

subnet 10.137.224.0 netmask 255.255.240.0 {
range 10.137.225.22. 10.137.225.30;
range 10.137.225.62 10.137.225.254;
# option routers rtr-239-0-1.example.org, rtr-239-0-2.example.org;
}

# This declaration allows BOOTP clients to get dynamic addresses,
# which we don't really recommend.

#subnet 10.254.239.32 netmask 255.255.255.224 {
# range dynamic-bootp 10.254.239.40 10.254.239.60;
# option broadcast-address 10.254.239.31;
# A slightly different configuration for an internal subnet.
#subnet 10.5.5.0 netmask 255.255.255.224 {
# range 10.5.5.26 10.5.5.30;
# option domain-name-servers ns1.internal.example.org;
# option domain-name "internal.example.org";
# option routers 10.5.5.1;
## option broadcast-address 10.5.5.31;
# default-lease-time 600;
# max-lease-time 7200;
#}

# Hosts which require special configuration options can be listed in
# host statements. If no address is specified, the address will be
# allocated dynamically (if possible), but the host-specific information
# will still come from the host declaration.

#host passacaglia {
# hardware ethernet 0:0:c0:5d:bd:95;
# filename "vmunix.passacaglia";
#3 server-name "toccata.fugue.com";
#}

# Fixed IP addresses can also be specified for hosts. These addresses
# should not also be listed as being available for dynamic assignment.
# Hosts for which fixed IP addresses have been specified can boot using
# BOOTP or DHCP. Hosts for which no fixed address is specified can only
# be booted with DHCP, unless there is an address range on the subnet
# to which a BOOTP client is connected which has the dynamic-bootp flag
# set.
#host fantasia {
# hardware ethernet 08:00:07:26:c0:a5;
#3 fixed-address fantasia.fugue.com;
#3}

# You can declare a class of clients and then do address allocation
# based on that. The example below shows a case where all clients
# in a certain class get addresses on the 10.17.224/24 subnet, and all
# other clients get addresses on the 10.0.29/24 subnet.

#class "foo" {
# match if substring (option vendor-class-identifier, 0, 4) = "SUNW";
#}
#shared-network 224-29 {
# subnet 10.17.224.0 netmask 255.255.255.0 {
# option routers rtr-224.example.org;
#}
# subnet 10.0.29.0 netmask 255.255.255.0 {
# option routers rtr-29.example.org;
#}
# pool {
# allow members of "foo";
# range 10.17.224.10 10.17.224.250;
# }
# pool {
# deny members of "foo";
# range 10.0.29.10 10.0.29.230;
# }
#}
next-server 10.137.226.129;
#filename "/tftpboot/menu.lst.01000C290E866C";
filename "01000C29695584";
host mumvmxsun11
{
#0:C:29:69:55:84 10.137.225.153
hardware ethernet 0:C:29:69:55:84;
}

So you have a dhcpcd server running?
Haw have you assigned that static IP ait's address? It's not picking it up by dhcp, by any chance? If you set
in your init scripts, thenit will get it's IP by dhcp. You need a static declaration of IP and

it is USE_DHCP= no

dhcpd is running !

Although whenever I run "dhcpd service restart" it comes back to my static ip. But again after some time it backs to the same problem, Is there any issue with selinux.

I personally detest selinux and nobble it to begin faultfinding. Some crude but effective global hack in selinux.conf.

dhcpcd is a client. Clients ask for IPs and set the nic IP accordingly. Servers sit there and give out IPs. I( know, servers end in 'd' (e.g. ftpd, xinetd, etc) and clients generally don't, but this one does. From 'man dhcpcd'
I would set up a static IP with ifconfig, or put the static ip into the init scripts. If you have a red hat type setup, include your static IP only. Dhcpcd should the not be run. Maybe you can sort this with system-config-network. It's been a while.