DNS lookup failed or very, very, slow.

Everyone thought it was bandwidth utilization but we brought in a new 50/10 circuit (this issue wasn’t the deciding factor) and it may have gotten worse.

Symptoms: Pages load slowly, I mean 56k slow but only sometimes, but frequently, or pages load halfway but on refresh almost instantly.

Since the latest chrome update it actually gives the « webpage is not available » error before eventually loading.

Environment: Windows – both DC and PDC are 2012, all workstations are W7. Only one domain in forest.

PDC refers to it’s self as preferred DNS server:

DC refers to PDC as Preferred DNS and it’s self as Alternate DNS.

Gateway points toward ISP’s DNS currently but I’ve changed that around in the past to see if that was the issue. No URL filtering or monitoring set up, DNS Lookup and Proxy are enabled.

Workstations DNS set to PDC, DC, and Gateway.

Another thing that makes me think it’s DNS related is that down and up speeds are normal, it’s only page loads that are slow.

Servers are showing no DNS errors. I’ve tried it with the AV disabled but issues persisted.

Any help or a point in a direction is appreciated.