Port 2664: Patrol for MQ GM — The Enterprise Monitoring Relic

What Port 2664 Is

Port 2664 (TCP and UDP) is registered to patrol-mq-gm — BMC Software's PATROL monitoring agent for IBM MQ (formerly MQSeries).¹ IBM MQ is enterprise middleware that lets applications pass messages to each other reliably; PATROL is BMC's infrastructure monitoring platform that watches those queues to ensure they're healthy.

The "GM" in the service name likely refers to a General Manager component in the PATROL architecture — the layer that coordinates between monitoring agents and the central PATROL console.

You won't encounter this port outside environments running BMC PATROL alongside IBM MQ. It lives in large enterprise data centers: financial institutions, insurance companies, telecom providers — anywhere IBM middleware is doing the work of moving critical transactions between systems.

The Registered Ports Range

Port 2664 falls in the registered ports range (1024–49151). Here's what that means:

• Well-known ports (0–1023): Reserved for core Internet protocols. HTTP, SSH, DNS. These require root/admin privileges to bind on most systems.
• Registered ports (1024–49151): Available for software vendors and projects to claim with IANA. No privilege required to bind. This is where enterprise software, databases, and application servers live.
• Dynamic/ephemeral ports (49152–65535): Unregistered. Used temporarily by operating systems for outbound connections.

The registered range is enormous — over 48,000 ports — and IANA has filled much of it with registrations from software that came and went. patrol-mq-gm is one of thousands of entries that represent products most people have never heard of.

Checking What's Listening

If you see port 2664 active on a system and want to know what's actually using it:

On Linux/macOS:

ss -tlnp | grep 2664
# or
lsof -i :2664

On Windows:

netstat -ano | findstr :2664
# Then look up the PID:
tasklist | findstr <PID>

If you're not running BMC PATROL and something is listening on 2664, that's worth investigating. Unexpected open ports are how you find rogue services, misconfigured software, or worse.

Why Unassigned Ports Matter

Even ports with no registered service — or obscure ones like this — matter for a few reasons:

Security scanning: Attackers scan for anything listening. A port left open unnecessarily is an attack surface, regardless of what the IANA registry says it's "for."

Firewall policy: Most organizations run default-deny egress and ingress policies, only allowing ports they explicitly need. Understanding the registered purpose of a port helps make that decision.

Incident response: When something unexpected appears in your firewall logs, the IANA registry is your first stop for "is this supposed to be here?"