Port 1496 sits in the registered port range (1024-49151), officially assigned by IANA to Liberty License Manager (liberty-lm).1 This is a software licensing service that manages licenses for commercial applications—the kind of infrastructure that runs quietly in the background of corporate networks, rarely noticed unless something breaks.
What Liberty License Manager Does
Software license managers track who's using what software, enforce concurrent user limits, and prevent unauthorized usage. When an application needs to verify its license, it connects to the license manager server—in this case, over port 1496.2
Liberty License Manager is one of many competing license management systems. Others include FlexLM, Sentinel, and RLM, each using their own ports and protocols. If you've ever launched professional software and seen a brief "checking license..." message, you've encountered this ecosystem.
The Port Range Context
Port 1496 lives in the registered ports range (1024-49151). These ports are assigned by IANA to specific services, but unlike well-known ports (0-1023), they don't require root privileges to bind to on Unix systems.3
Registered ports are requested by organizations that want a stable, recognized port number for their service. Someone at Liberty License Manager submitted an application to IANA, and 1496 became theirs.
The Confusion About S-HTTP
Many port databases incorrectly claim port 1496 runs S-HTTP (Secure HTTP). This is wrong.
S-HTTP was an early attempt at securing web traffic, defined in RFC 2660.4 It competed with HTTPS and lost—HTTPS uses port 443 and became the standard, while S-HTTP faded into obscurity. S-HTTP typically operated on port 80 (the same as regular HTTP), not port 1496.5
The confusion likely stems from outdated port databases that copy information from each other without verification. Port 1496 is registered for Liberty License Manager, not S-HTTP.
Security: The Bionet Trojan Connection
Port 1496 has an unpleasant history in security circles. The Bionet trojan (versions 3.13-3.18) used port 1496 for command-and-control communications.6 When infected systems connected to their controller, they did so over this port.
This doesn't mean port 1496 is inherently dangerous—it means malware authors sometimes choose registered ports to blend in with legitimate traffic. If you see unexpected connections on port 1496 and you're not running Liberty License Manager, investigate.
Security scanners sometimes flag port 1496 as a "virus port" because of this historical association.7 The presence of the port alone doesn't indicate infection, but it warrants verification.
How to Check What's Using Port 1496
On Linux or macOS:
On Windows:
These commands show which process, if any, has port 1496 open. If you see a connection and don't recognize the process, investigate further.
Why This Port Matters
Most people will never encounter port 1496. It's not part of everyday Internet infrastructure like DNS (53) or HTTPS (443). But it represents something important about how the Internet's nervous system works.
Thousands of registered ports exist for specialized services—license managers, industrial protocols, proprietary databases, legacy systems. These ports form the long tail of network services, invisible to most users but critical to the organizations that depend on them.
Port 1496 is one of those quiet workers. It manages software licenses somewhere in a corporate network, unremarked and unremarkable—until a trojan borrows it, or a security scanner flags it, or someone wonders what that mysterious connection is.
Related Ports
- Port 27000-27009 — FlexLM license manager (another common licensing system)
- Port 1947 — Sentinel license manager
- Port 5053 — RLM license manager
Frequently Asked Questions About Port 1496
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