We have two dhcp failover servers and today noticed in the log files one of the servers reporting peer holds all leases and the other saying not authoritiive. There are free leases available on the subnets, the problem occurs with existing pc's already registered, registereing new pc's is worknig fine. we tried release an existing ip on a pc that was working and renewing and it wouldn;t allow messages on dhcp service log was - discover only thats as far as it got, there ahve been no changes made over the last few weeks apart from one minor change to the dhcp master file which was editing an ip subnet i ahve checked to see if there are any other changes to that file and the only thing i could find as it was not me who made the change was the time stamp on our dhcp managemtn server (which is also our ntp server) had the correct time stamp on the master dhcp file but when i checked the time stamp on the master file on the dhcp files it was different and had an older time-4 hours prior to this, i dont think this is the reason but i thought maybe worth noting. Neither of the servers have been rebooted, nor have dhcp.leases purged, not sure what route to go down, theya re pretty old servers. Thank in advance for any assistance with this.