after upgrading the ios to 15.2 i got a problem in DNS resolving at windows server 2019. i checked all the possible solutions but only possible problem there is a miss configuration at the switch . please note that i can ping 8.8.8.8 and 8.8.4.4 . but not able to open google.com for example . here i list you the configuration for
Microsoft said that the Windows Update service was impacted by a data corruption issue with an external DNS provider. The company didn’t give anymore details other than that and it did not name the Windows 10 - DNS Issue - Microsoft Community Sep 18, 2017 How to Fix DNS Server Not Responding Problem (with Pictures)
DNS Error - Event ID - 4015
Wormable DNS flaw endangers all Windows servers | CSO Online Wormable DNS flaw endangers all Windows servers The SIGRed vulnerability can spread malware across a network without user interaction. Microsoft has issued an urgent patch.
Apr 29, 2020
Jan 13, 2003 Windows 10: How to Flush and Reset the DNS Cache Dec 20, 2018 How to fix the "DNS server unavailable" error on Windows Jul 12, 2020 DNS problem - social.technet.microsoft.com