First guess is that you may have two devices on the network with the same ip address. Next time this happens, try doing 1. 'arp -n' from a machine other than the db server 2. ping the other machine from the db server, then 3. 'arp -n' from the other machine Compare the outputs of the two invocations of arp. If the outputs show different MAC addresses for 192.168.41.4 then you have two different devices with the same IP address.