I think this is a bug: CentOS 5.4 using Samba 3.4.7. If the server IP address changes, nmbd complains every few minutes that "There is already a domain master browser" on the old IP address. Although "Chapter 41. Managing TDB Files" states: wins.dat N WINS database iused only when wins support = yes has been set. This gets rebuilt or updated at every restart. that does not appear to be the case, since manually deleting wins.dat and restarting Samba makes the problem go away. Steps to reproduce: Server IP address 10.32.1.201 running Samba: # rpm -qa samba3\* libsmb\* libwb\* kernel samba3-client-3.4.7-42.el5 samba3-cifsmount-3.4.7-42.el5 samba3-3.4.7-42.el5 samba3-doc-3.4.7-42.el5 libwbclient0-3.4.7-42.el5 samba3-winbind-3.4.7-42.el5 kernel-2.6.18-164.15.1.el5 # service smb status smbd (pid 2591 2548) is running... nmbd (pid 2552 2551) is running... # ip addr list up 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 1000 link/ether 00:0c:29:dd:52:71 brd ff:ff:ff:ff:ff:ff inet 10.32.1.201/24 brd 10.32.1.255 scope global eth0 inet6 fe80::20c:29ff:fedd:5271/64 scope link valid_lft forever preferred_lft forever # testparm -s | grep interfaces interfaces = 10.32.1.201/255.255.255.0 Now change the server's IP address by editing ifcfg-eth0 and smb.conf to change 10.32.1.201 to 10.32.1.200. Reboot the server. # service smb status smbd (pid 2591 2548) is running... nmbd (pid 2552 2551) is running... # ip addr list up 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 1000 link/ether 00:0c:29:dd:52:71 brd ff:ff:ff:ff:ff:ff inet 10.32.1.200/24 brd 10.32.1.255 scope global eth0 inet6 fe80::20c:29ff:fedd:5271/64 scope link valid_lft forever preferred_lft forever # testparm -s | grep interfaces interfaces = 10.32.1.200/255.255.255.0 # ping 10.32.1.201 PING 10.32.1.201 (10.32.1.201) 56(84) bytes of data.