For Cisco Prime Infrastructure to process client host name values successfully, DNS queries need to be returned in less than 2 seconds. Under some circumstances, even with faster DNS responses, the Prime Infrastructure server may flag the DNS server as down and will not query it for 30 minutes, causing a "no client hostname" value to be reported on some wired and wireless clients.
Fixing the Missing Client Hostnames
Users experiencing this problem can work around it using either of the following methods:
1. Increase the Prime Infrastructure default setting for DNS timeouts. You can do this by changing the value (the unit must be in seconds) for the attribute HostName.Threshold in the Prime Infrastructure properties file /opt/CSCOlumos/conf/rfm/classes/com/cisco/server/resources/ClientParameters.properties. Once you have made this change, you will need to restart the Prime Infrastructure server in order for the change to be applied (for details, see Restarting Prime Infrastructure).
2. Configure Prime Infrastructure to enable DNS hostname lookup and specifying a DNS server that has a very fast response time. For more details, see Enabling DNS Hostname Lookup.