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registry hardening
About this tag
Registry hardening involves modifying Windows registry settings to reduce security risks. A key example is mitigating DNS cache poisoning on Windows DNS servers by setting the MaximumUdpPacketSize registry value to 1221 bytes, forcing large responses over TCP instead of UDP. This applies to Windows Server 2022, 2025, and other recent builds. Registry hardening is a practical, low-level security measure for enterprise IT environments.
Microsoft has updated guidance in its Security Update Guide advisory ADV200013 — the advisory that covers DNS resolver spoofing and cache‑poisoning attacks — and is explicitly telling administrators that in addition to older server builds the mitigation applies to newer releases such as Windows...
1221
adv200013
dns
dns cache
dns forwarders
dns over tcp
dns registry
dns security
edns0
firewall dns tcp
maximumudppacketsize
powershell
registryhardening
security tips
server core
tcp dns latency
windows server
windows server 2022
windows server 2025