{"id":4279,"date":"2026-04-30T15:01:51","date_gmt":"2026-04-30T19:01:51","guid":{"rendered":"https:\/\/increasec.com\/?p=4279"},"modified":"2026-04-30T15:04:13","modified_gmt":"2026-04-30T19:04:13","slug":"dc-wont-dc-anymore","status":"publish","type":"post","link":"https:\/\/increasec.com\/?p=4279","title":{"rendered":"DC won’t DC anymore"},"content":{"rendered":"\n

Had a Windows Server 2016 DC acting strange.<\/p>\n\n\n\n

<\/p>\n\n\n\n

Symptoms:<\/p>\n\n\n\n

ping successful, DNS all correct<\/p>\n\n\n\n

Firewall is off, AV is disabled<\/p>\n\n\n\n

browsing any share including NETLOGON fails<\/p>\n\n\n\n

DC thinks tcp 445 is listening<\/p>\n\n\n\n

PS C:\\share> netstat -ano | findstr :445
  TCP    0.0.0.0:445            0.0.0.0:0              LISTENING       4
  TCP    10.10.5.11:26029       10.10.5.112:445        ESTABLISHED     4
  TCP    [::]:445               [::]:0                 LISTENING       4<\/p>\n\n\n\n

<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

Test-NetConnection nfgserver -Port 445 -InformationLevel Detailed
WARNING: TCP connect to (10.10.5.11 : 445) failed<\/p>\n\n\n\n

ComputerName\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 : nfgserver
RemoteAddress\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 : 10.10.5.11
RemotePort\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 : 445
NameResolutionResults\u00a0\u00a0 : 10.10.5.11
MatchingIPsecRules\u00a0\u00a0\u00a0\u00a0\u00a0 :
NetworkIsolationContext : Private Network
InterfaceAlias\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 : Ethernet 2
SourceAddress\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 : 10.10.5.104
NetRoute (NextHop)\u00a0\u00a0\u00a0\u00a0\u00a0 : 0.0.0.0
PingSucceeded\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 : True
PingReplyDetails (RTT)\u00a0 : 0 ms
TcpTestSucceeded\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 : False<\/p>\n\n\n\n

<\/p>\n\n\n\n

Fix:<\/p>\n\n\n\n

reg add HKLM\\SYSTEM\\CurrentControlSet\\Services\\LanmanServer\\Parameters \/v DisableStrictNameChecking \/t REG_DWORD \/d 1 \/f<\/p>\n\n\n\n

net stop lanmanserver<\/p>\n\n\n\n

net start lanmanserver<\/p>\n\n\n\n

<\/p>\n\n\n\n

ODD:<\/p>\n\n\n\n

the server was imported from Hyper-V, it has a ghost network adapter (greyed out), was this InterfaceAlias?<\/p>\n\n\n\n

no reverse DNS, eventually created zone<\/p>\n","protected":false},"excerpt":{"rendered":"

Had a Windows Server 2016 DC acting strange. Symptoms: ping successful, DNS all correct Firewall is off, AV is disabled browsing any share including NETLOGON fails DC thinks tcp 445…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[81],"class_list":["post-4279","post","type-post","status-publish","format-standard","hentry","category-uncategorised","tag-microsoft"],"_links":{"self":[{"href":"https:\/\/increasec.com\/index.php?rest_route=\/wp\/v2\/posts\/4279","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/increasec.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/increasec.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/increasec.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/increasec.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=4279"}],"version-history":[{"count":2,"href":"https:\/\/increasec.com\/index.php?rest_route=\/wp\/v2\/posts\/4279\/revisions"}],"predecessor-version":[{"id":4283,"href":"https:\/\/increasec.com\/index.php?rest_route=\/wp\/v2\/posts\/4279\/revisions\/4283"}],"wp:attachment":[{"href":"https:\/\/increasec.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=4279"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/increasec.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=4279"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/increasec.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=4279"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}