dhclient(3108) is already running - exiting. This version of ISC DHCP is based on the release available on ftp.isc.org. Features have been added and other changes have been made to the base software release in order to make it work better with this distribution. Please report for this software via the CentOS Bugs Database: http://bugs.centos.org/ exiting.
[root@localhost ~]# ps -ef | grep dhclient root 3108 1 0 04:36 ? 00:00:00 dhclient root 4140 3013 0 05:16 pts/0 00:00:00 grep dhclient
[root@localhost ~]# kill -9 3108