We're considering ways to provide redundant DHCP to maintain service should our (physical) server go down suddenly. We're using isc-dhcpd on RHEL. One server handles all of campus, and it's not breaking a sweat.
Our first thought was ISC's failover, but it doesn't seem well-suited for us. We have a large and complex DHCP config (many subnets, many static hosts), and failover doesn't keep the configs in sync. Further, the config changes near-constantly during the day. Our wireless network registration system (NetReg 1.3) stuffs new registrations into the DHCP config (via an included file). We also have concerns about how IP pool-sharing works, but that's secondary. How do other shops provide redundant DHCP service when the built-in isc-dhcpd failover isn't appropriate? We've planned a fairly hacky solution, but I really hope it's an already-solved problem. Our plan is to: * Maintain the backup server as a hot-spare, with dhcpd configured but not running. It won't run the registration software, just dhcpd to maintain service to existing clients. * Whenever a registration event causes the master dhcpd to restart, copy that config and the leases DB to the backup server. There's already a cron job that checks every minute for new registrations and restarts dhcpd if so; we'd hook into that. (The details of this are tricky -- what happens, say, if the master server dies in the middle of a copy? We can surmount that, but still.) * Should the master server go down, we'd sanity-check the config on the backup, and turn on dhcpd. This could be a manual or automatic process. I'd be grateful for pointers to other ways, or comments on the above scheme. Thanks, Aaron -- Aaron Hall <aaron.h...@washburn.edu> Asst. Systems & Network Administrator Washburn University ITS 785-670-2305 _______________________________________________ Tech mailing list Tech@lists.lopsa.org https://lists.lopsa.org/cgi-bin/mailman/listinfo/tech This list provided by the League of Professional System Administrators http://lopsa.org/
