For further analysis, I recommend to attach strace -tt /root/dhcpd.strace $(pidof dhcpd) to the running server. Dec 17 15:29:47 littleboy dhcpd: Cannot search for (&(objectClass=dhcpHost)(dhcpHWAddress=ethernet 00:d0:b7:c1:15:84)) in LDAP tree cn=morrison-primary,ou=Configs,ou=ISCdhcpDaemon,ou=SubSystems,o=Morrison Industries,c=US: Can't contact LDAP server nohup strace -tt -o /root/dhcpd.strace -p 20296 & Can you provide 'lsof -p $(pidof dhcpd)' output as well please? (Assuming that file descriptors are the same from run to run; better capture lsof output together with fresh strace)
littleboy:~ # lsof -p 26678 COMMAND PID USER FD TYPE DEVICE SIZE NODE NAME dhcpd 26678 dhcpd cwd DIR 253,5 168 35750 /var/lib/dhcp dhcpd 26678 dhcpd rtd DIR 253,5 168 35750 /var/lib/dhcp dhcpd 26678 dhcpd txt REG 253,5 576464 35780 /usr/sbin/dhcpd dhcpd 26678 dhcpd mem REG 253,5 106308 3094 /lib/ld-2.3.3.so dhcpd 26678 dhcpd mem REG 253,5 232916 35274 /usr/lib/libldap-2.2.so.7.0.8 dhcpd 26678 dhcpd mem REG 253,5 57741 35272 /usr/lib/liblber-2.2.so.7.0.8 dhcpd 26678 dhcpd mem REG 253,5 1359489 3120 /lib/tls/libc.so.6 dhcpd 26678 dhcpd mem REG 253,5 73086 3115 /lib/libresolv.so.2 dhcpd 26678 dhcpd mem REG 253,5 94878 67560 /usr/lib/libsasl2.so.2.0.19 dhcpd 26678 dhcpd mem REG 253,5 219497 30507 /usr/lib/libssl.so.0.9.7 dhcpd 26678 dhcpd mem REG 253,5 1135011 30505 /usr/lib/libcrypto.so.0.9.7 dhcpd 26678 dhcpd mem REG 253,5 13072 3103 /lib/libdl.so.2 dhcpd 26678 dhcpd mem REG 253,5 41661 3109 /lib/libnss_files.so.2 dhcpd 26678 dhcpd mem REG 253,5 217016 35690 /var/run/nscd/passwd dhcpd 26678 dhcpd mem REG 253,5 217016 35691 /var/run/nscd/group dhcpd 26678 dhcpd 0u REG 253,5 50893 53281 /var/lib/dhcp/db/dhcpd.leases dhcpd 26678 dhcpd 3u unix 0xef042e20 1684142 socket dhcpd 26678 dhcpd 4u raw 1684148 00000000:0001->00000000:0000 st=07 dhcpd 26678 dhcpd 5u IPv4 1684154 TCP localhost:33983->localhost:ldap (ESTABLISHED) dhcpd 26678 dhcpd 7u IPv4 1684161 UDP *:bootps dhcpd 26678 dhcpd 8u IPv4 1684160 UDP *:bootps dhcpd 26678 dhcpd 9u IPv4 1684162 TCP *:7911 (LISTEN) Will post the tail of 'strace -tt -o /root/dhcpd.strace -p 26678' as soon as it dies. BTW, dhcpd is running as "/usr/sbin/dhcpd -chroot /var/lib/dhcp/ -lf /db/dhcpd.leases -user dhcpd -group nogroup eth0"
Does the dhcp server have a direct TCP connection with the LDAP server? No NAT being done in between?
DHCP server is connecting to "localhost", iptables are empty, all default policies are accept. littleboy:~ # iptables -L Chain INPUT (policy ACCEPT) target prot opt source destination Chain FORWARD (policy ACCEPT) target prot opt source destination Chain OUTPUT (policy ACCEPT) target prot opt source destination I disabled all firewall rules at the beginning of this problem, to assist with troubleshooting.