Port 3669: CA SAN Switch Management — Enterprise Storage, Quietly Registered

What Port 3669 Does

Port 3669 is officially assigned to CA SAN Switch Management (service name: casanswmgmt), registered with IANA in January 2003.¹ It operates on both TCP and UDP.

The "CA" is Computer Associates — later CA Technologies, now part of Broadcom after a 2018 acquisition. The port was designed for managing Storage Area Network (SAN) switches: dedicated high-speed networks that connect servers to shared storage arrays in large enterprise environments.

SANs sit behind the scenes in data centers. While your application talks to a server over the regular network, the server talks to its storage over a SAN — a separate, dedicated fabric optimized for block-level storage traffic. Managing the switches in that fabric is what this port was built for.

Why You Probably Haven't Seen It

This is enterprise infrastructure from a specific era. The SAN management tools that used this port were deployed in large corporate data centers, not on the open Internet. If you've never administered a legacy CA storage product, you've likely never seen traffic on 3669.

Modern storage management has largely moved to different protocols and interfaces. The products this port served have been absorbed, replaced, or deprecated through two decades of enterprise software consolidation.

The Registered Port Range

Port 3669 sits in the registered port range: 1024 through 49151.

• Well-known ports (0–1023): Reserved for core protocols — HTTP, HTTPS, SSH, DNS. Require root/admin privileges to bind.
• Registered ports (1024–49151): Available for applications to register with IANA. No special privileges required to bind. This is where most named services live.
• Dynamic/ephemeral ports (49152–65535): Assigned on the fly by the OS for outbound connections. Not registered to any service.

Registration in this range means IANA recorded the assignment, but it doesn't mean every operating system blocks or reserves the port. If the CA software isn't running, something else can use 3669 without conflict.

What to Do If You See It

If port 3669 shows up on a machine you administer and you're not running CA storage management software, check what's actually listening:

Linux/macOS:

ss -tlnp | grep 3669
# or
lsof -i :3669

Windows:

netstat -ano | findstr :3669

Cross-reference the process ID against your running services. An unexpected listener on a registered port is worth investigating — not because the port itself is suspicious, but because unrecognized listeners generally are.