Tag Archives: dns

Powershell: Batch update of DNS server list in ESXi hosts

A quick one-liner to update the DNS serer list of all ESXi hosts in a cluster.

get-vmhost -location "MyVMClusterName |
get-vmhostnetwork |
set-vmhostnetwork -dnsaddress "",""

Leave a comment

Posted by on June 28, 2013 in powershell, Scripts, vmware


Tags: , , ,

Long DHCP lease causes client’s DNS name to disappear

Recently, we found that some servers’ and workstations’ host record (A RR) has been dropped off our DNS servers. All the machines were running a DHCP clients and we are using MS product for both DHCP and DNS.

The DHCP servers are configured to update the host record on behalf of the client. When we checked the scopes, we found that they have a 30 days lease duration. Very quickly it was established that its possible that the host records could have gone stale in the DNS due to the lease duration and got scavenged.

A quick chat with our DNS team and we found our that the DNS servers have a setting of about 14 days before a record is scavenged in a daily routine. Namingly the values are 7 days for non-refresh interval and 7 days for refresh interval.  (see DNS Aging/Scavenging Simplied) Read the rest of this entry »

Leave a comment

Posted by on May 29, 2009 in Windows


Tags: ,