At 11:54 25/01/2002 +0000, Fred Clausen wrote:
Hi all, At the moment I have one dhcp server running ISC dhcpd, and its working fine. However I wish to add another in case the main one goes down. Is it as simple as setting it up on another machine with similar config? My worry is that a client will request an address and both server's will respond, potentially causing problems. Is there a master/slave setup I can use? Or shall I simply set up a second one.
As far as I know this isn't possible for a few reasons. The lease table for IP's already allocated is stored in a file on the system. To have failover your second machine would have to have a copy of this file locally. Secondly as you mentioned both servers will respond and whichever machine reply get to the client first is the one it will accept. If you could get the dhcpd.lease filesynced in realtime it should be possible.. but it would be messy at best. I haven't looked into this for a while and there maybe a better way to do it now.
The other option is have the second machine as a complete failover and use a heartbeat much like the current mailserver thread is going
Dave