Port 1715: houdini-lm — The Gatekeeper for Hollywood's Effects Engine

Port 1715 is registered with IANA as houdini-lm — the license management port for SideFX Houdini, the 3D simulation and visual effects software used in productions like Dune, Interstellar, and countless other films and games.¹

Before Houdini does anything — before it simulates a single particle or renders a single frame — it contacts a license server. That server listens on port 1715.

What Runs on This Port

The license server daemon is called sesinetd. It runs on a central license server machine in a studio's network and fields requests from every Houdini workstation. When an artist launches Houdini, the software contacts hserver (a local helper running on the client, on port 1714), which in turn contacts sesinetd on port 1715 to check out a license.²

The handshake is simple: "Do you have a license available?" If yes, the software runs. If not, the artist waits.

In a large VFX studio, dozens of seats might be checked in and out across port 1715 throughout the day — morning rush when artists arrive, midday churn as render farms spin up, evening quiet as everyone goes home and licenses flow back into the pool.

The Port Pair: 1714 and 1715

These two ports work together:

Firewalls at studios that use Houdini need both ports open between client machines and the license server.³

What Range This Port Belongs To

Port 1715 sits in the registered ports range (1024–49151). These ports aren't reserved for core Internet infrastructure — they're available for applications to register with IANA for a specific, named use. Registration doesn't grant exclusive enforcement; it just marks intent and reduces accidental collisions.

IANA registration means port 1715 is officially associated with houdini-lm, though nothing stops another application from using it on a private network.

Checking What's Listening on This Port

# macOS and Linux
sudo lsof -i :1715

# Linux alternative
ss -tlnp | grep 1715

# Windows
netstat -ano | findstr :1715

If you're running Houdini in a network-licensed environment, you'll see sesinetd here. On most machines, you'll see nothing.