Tag: Windows Firewall

Systems Admin

Troubleshoot “The Specified Server Cannot Perform the Requested Operation” Error (0x3a)

Domain join error 0x3a (The specified server cannot perform the requested operation) is almost always a TCP 389 LDAP connectivity problem dressed up in directory-layer language. This article walks the diagnostic path: confirm DNS and basic reachability, prove TCP 389 with Test-NetConnection, then narrow the block to the workstation host firewall, the DC host firewall, or the network ACL between them. Includes the multi-port sweep (53/88/135/389/445/464/3268), the residual-causes list when port 389 is open (AD DS service, time skew, stale computer object), and the common pitfalls (disabled firewall left off, public DNS resolver, 389-vs-636 confusion).

10 min read
Read →
Systems Admin

Disable Windows Firewall with PowerShell

When you legitimately need to turn the host firewall off (debugging, lab, migration window) and how to do it cleanly with PowerShell. Get-NetFirewallProfile reads the per-profile state; Set-NetFirewallProfile -Enabled False flips them off; the same cmdlet with True flips them back. Includes the targeted-single-rule alternative (Disable-NetFirewallRule), a try/finally cleanup pattern, the schedule-a-forcing-function-to-re-enable pattern, and the common pitfalls (forgot to re-enable, wrong profile, GPO override, trusted-the-wrong-tool).

7 min read
Read →
Systems Admin

Enable Windows Firewall with PowerShell

Re-enable Windows Defender Firewall on a Windows Server with one cmdlet per profile. Get-NetFirewallProfile reads the per-profile state (Domain / Private / Public); Set-NetFirewallProfile -Enabled True flips them all on at once. Covers the three profiles, the read-then-set-then-verify pattern, the rest of the per-profile properties (default actions, logging, notifications), per-rule operations (New-NetFirewallRule, Get-NetFirewallRule, Enable/Disable), and the common pitfalls (turned off for testing, disabled only one profile, GPO override, block-all-outbound footgun).

8 min read
Read →