Dear Experts, I was running ISC DHCP server for longer than I would care to remember. Now I decided to climb out of the cave and configure failover set (primary-secondary), and I seem to hit brick wall, which I need help with. I only need IP v4, no v6, which may simplify things. Could someone point to a description of working DHCP failover configuration? I do not want to make two independent DHCP servers handling half of the pool each. We are not that rich as far as IP space is concerned. I am not married to ISC DHCP server, so any one I will do, because: <rant> My current configuration is something that was gradually migrated and/or adjusted through several generations of systems, and server versions over the years. It works. When I tried to incorporate what I need for failover following ISC documentation, and some people's guides, I discovered, I need more sophisticated structure of sections and subsections, which I figured out finally. But the annoying part was: in ISC documentation I failed to find general stricture of which section can appear inside which; like: a { b { c { } } } You can create each of sections/subsections following documentation, but to put them together making consistent config file you (I at least) have to figure on your own which section goes inside of which. </rant> So, I am not married to ISC DHCP server, we didn't get along now as far as my use of documentation is concerned. Anything that works - with failover! I am going to have it set up on FreeBSD, but if something works on Linux, I likely will be able to reproduce it on FreeBSD. Thanks in advance for all your answers! Valeri -- ++++++++++++++++++++++++++++++++++++++++ Valeri Galtsev Sr System Administrator Department of Astronomy and Astrophysics Kavli Institute for Cosmological Physics University of Chicago Phone: 773-702-4247 ++++++++++++++++++++++++++++++++++++++++