Clients on our wireless network has been experiencing an issue where they are not able to go out onto the internet due to a DNS error. On the Connectivity timeline reads "Disabled gateway (bad DNS)". At first we thought this meant our local DNS had some issue, but upon changing the DHCP settings of the wireless network to use Google's DNS (126.96.36.199), the error messages still read the same.
What could be the cause of this intermittent problem?
Note: outages last around 12 minutes and may occur between 1 to 4 times within 24 hours.