Hamachi Inbound Traffic - Blocked

Windows Filtering Platform (WFP) blocks Hamachi. Navigate to: HKLM\SYSTEM\CurrentControlSet\Services\Hamachi2\Parameters Create DWORD: AllowInbound = 1

LogMeIn Hamachi is a zero-configuration VPN that facilitates virtual local area networks (VLANs). However, a pervasive issue reported across Windows, macOS, and Linux clients is the — where a peer can send data out (egress) but cannot receive data from other network members (ingress). This report analyzes the root causes, diagnostic methods, and comprehensive solutions for inbound traffic blocks in Hamachi environments. hamachi inbound traffic blocked

Use a Hamachi gateway with port forwarding manually configured: forward UDP 12975 to the Hamachi client’s internal IP. Windows Filtering Platform (WFP) blocks Hamachi

: If you are on macOS, ensure you have clicked Allow in System Preferences > Privacy & Security for software from developer "LogMeIn, Inc." [19]. This report analyzes the root causes, diagnostic methods,

| Factor | Impact on Hamachi Inbound | |--------|----------------------------| | Symmetric NAT | Blocks UDP hole punching; forces relay | | ISP-level CGNAT | Prevents direct inbound; only relay works | | Double NAT | Same as symmetric NAT | | UPnP disabled | Hamachi cannot auto-forward ports |

Location: %windir%\system32\LogFiles\Firewall\pfirewall.log Look for: DROP for source port 12975/12976 or destination IP in 5.x.x.x range.

:In the Advanced Security settings of your firewall, right-click Windows Defender Firewall Properties . Under each profile tab (Domain, Private, Public), click Customize next to "Protected network connections." Uncheck the Hamachi network adapter to prevent the firewall from applying its default filters to Hamachi traffic [3].