when redhat 6.1 i386 was installed it was set to use dhcp. as soon as installation was finished, the ip assignement was changed to manual via linuxconf. an ip different from the one previously obtained via dhcp was used. the new manually assigned ip works correctly, but the dhcp client is still sending a dhcp request to the dhcp server. when the server responds, the dhcp client ignores it. the dhcp client again requests an ip a few seconds later, then ignores the response, ... ad infinitum this bug does not in any way interfere with the proper working of the computer or its networking. it just fills the log of the dhcp server. restarting network interface did not stop the behavior so i rebooted the computer, thus fixing the problem. here is a sample from the log of my dhcp server (dhcpd from bind distribution, openbsd 2.5): Dec 2 19:10:14 nexus dhcpd: DHCPREQUEST for 192.168.1.23 from 00:60:b0:b4:6a:f9 via le2 Dec 2 19:10:14 nexus dhcpd: DHCPACK on 192.168.1.23 to 00:60:b0:b4:6a:f9 via le2 Dec 2 19:10:14 nexus dhcpd: DHCPREQUEST for 192.168.1.23 from 00:60:b0:b4:6a:f9 via le2 Dec 2 19:10:14 nexus dhcpd: DHCPACK on 192.168.1.23 to 00:60:b0:b4:6a:f9 via le2 Dec 2 19:10:14 nexus dhcpd: send_fallback: Host is down Dec 2 19:10:17 nexus dhcpd: DHCPREQUEST for 192.168.1.23 from 00:60:b0:b4:6a:f9 via le2 Dec 2 19:10:17 nexus dhcpd: DHCPACK on 192.168.1.23 to 00:60:b0:b4:6a:f9 via le2 Dec 2 19:10:17 nexus dhcpd: send_fallback: Host is down Dec 2 19:10:17 nexus dhcpd: DHCPREQUEST for 192.168.1.23 from 00:60:b0:b4:6a:f9 via le2 Dec 2 19:10:17 nexus dhcpd: DHCPACK on 192.168.1.23 to 00:60:b0:b4:6a:f9 via le2 Dec 2 19:10:17 nexus dhcpd: send_fallback: Host is down
You need to "ifdown" and "ifup" a device after reconfiguring it.