Port 2238: AVIVA SNA Server — A Bridge to IBM's Mainframe Era

What This Port Is

Port 2238 is registered with IANA under the service name aviva-sna — the AVIVA SNA Server. Both TCP and UDP are assigned.

AVIVA Solutions built host access software for enterprises running IBM mainframes and AS/400 systems. In the 1990s, this was serious business: corporate data lived on IBM iron, and getting that data to Windows desktops required dedicated software that spoke both worlds. AVIVA's SNA Server was one such bridge, using port 2238 as its communication channel.

SNA — Systems Network Architecture — was IBM's proprietary networking stack, developed in 1974. It predates TCP/IP's dominance and operates on fundamentally different assumptions about how networks should work. SNA networks are hierarchical; TCP/IP networks are flat and distributed. Translating between them required real effort, and products like AVIVA SNA Server were built to do exactly that.

The Registered Port Range

Port 2238 sits in the registered port range (1024–49151). These ports aren't reserved for core Internet infrastructure like the well-known ports below 1024 — but they're not random either. Companies and developers register them with IANA to signal "this is ours; please don't accidentally use it for something else."

The registration system is voluntary and imperfect. IANA keeps the list, but enforcement is nonexistent. If you want to use port 2238 for your own application, nothing stops you — you just might conflict with anyone still running AVIVA SNA Server, which in 2026 is a very small population.

Is Anyone Actually Using This Port?

Almost certainly not at scale. IBM SNA networks have been largely retired or migrated to TCP/IP. AVIVA's mainframe connectivity products are legacy software serving organizations that haven't yet completed migrations — a shrinking group.

If you see traffic on port 2238, it's most likely one of:

• A genuine AVIVA SNA Server installation (rare)
• An application that chose this port without checking the registry
• A scanner probing your system

How to Check What's Listening

If you want to see whether anything on your own machine is using port 2238:

Linux/macOS:

# Show processes listening on port 2238
ss -tlnp sport = :2238

# Or with lsof
lsof -i :2238

Windows:

netstat -ano | findstr :2238

If nothing returns, nothing is listening. That's the expected result on any modern system.

Why Unassigned-Looking Ports Still Matter

Even registered-but-dormant ports like 2238 serve a purpose in the ecosystem. They're a historical record: someone built something, named it, filed for a number, and shipped software. The port registry is, among other things, a graveyard of technologies that once mattered — each number a small artifact of how networking evolved.

When your firewall logs show a probe on port 2238, you're probably looking at an automated scanner working through the registered range, not someone specifically targeting AVIVA SNA infrastructure. Block it if you have no reason to allow it.