slow dns troubleshooting

[hmc2500]

Can anyone advise how to best troubleshoot slow dns issues? Are there any helpful tools? When slow dns occurs the problem is sometimes very elusive and not obvious and may take hours before you finally realize the cause.

[Georg Pauwen]

Hello,

in what context ? What does your topology look like ? 

[hmc2500]

Sorry this is not a real routing issue but just something I wish would be easier to isolate. in my case the users were complaining about slow applications such as office 365 email and Teams. The corporate dns forwarders were pointing to open dns servers and having issues.

I just wonder how you guys go about dealing with or troubleshooting these issues.

[MHM Cisco World]

slow can happened when you have multi DNS server and the failed of one to failover to other is take sometime, 
and Yes this need some solution.