After a recent YOU update to SuSE 10.0, Linux became unable to reacquire a DHCP lease. When booting everything worked, but after the first lease expires, an infinite loop would occur:

Dec 21 21:13:24 sr1650nx dhcpcd[11655]: DHCP_NAK server response
Dec 21 21:13:24 sr1650nx dhcpcd[11655]: DHCP_NAK server response
Dec 21 21:13:25 sr1650nx modify_resolvconf: restored /etc/resolv.conf.saved.by.dhcpcd.eth0 to /etc/resolv.conf
Dec 21 21:13:25 sr1650nx kernel: eth0: link up, 100Mbps, full-duplex, lpa 0x41E1
Dec 21 21:13:26 sr1650nx modify_resolvconf: Service dhcpcd modified /etc/resolv.conf. See info block in this file
Dec 21 21:13:26 sr1650nx syslog-ng[11379]: SIGHUP received, restarting syslog-ng
Dec 21 21:13:26 sr1650nx ifdown: eth0 device: Realtek Semiconductor Co., Ltd. RTL-8139/8139C/8139C+ (rev 10)
Dec 21 21:13:26 sr1650nx ifdown: eth0 configuration: eth-id-00:13:d4:68:7b:1c
Dec 21 21:13:27 sr1650nx ifup: eth0 device: Realtek Semiconductor Co., Ltd. RTL-8139/8139C/8139C+ (rev 10)
Dec 21 21:13:27 sr1650nx syslog-ng[11379]: new configuration initialized
Dec 21 21:13:27 sr1650nx syslog-ng[11379]: Changing permissions on special file /dev/xconsole
Dec 21 21:13:27 sr1650nx syslog-ng[11379]: Changing permissions on special file /dev/tty10
Dec 21 21:13:27 sr1650nx dhcpcd[11655]: DHCP_NAK server response received

I assumed that my system had become damaged, since the download was not dhcpcd specific (it was kernel and apparmor). Eventually I decided to install openSuSE 10.2 in a spare partition. It exhibits the same problem.

This eliminates damage specific to my SuSE 10.0 installation and says I have a problem between dhcpcd and my Linksys router/dhcp server.