What Lives Here
Port 677 is officially assigned to Virtual Presence Protocol (VPP)—both TCP and UDP.1 This protocol was designed to enable the exchange of document-based virtual presence information. In simpler terms: it wanted to tell you when other people were reading the same web page you were.
The idea was to create "virtual neighborhoods" where you could see your virtual neighbors—other users who were close to you in virtual document space, not physical space.2
The Protocol That Never Was
VPP was documented in an Internet Draft in January 1999.3 The timing is interesting—this was before social media, before "presence" became something every platform tracked, before we expected to know what everyone was doing online at all times.
The protocol tried to solve a problem that actually mattered: how do you know if someone else is exploring the same corner of the Internet you are? Could you turn isolated web browsing into a shared experience?
VPP wasn't trying to replace instant messaging presence (like "away" or "online"). It was trying to add location—where you were in the virtual world of hyperlinked documents. The protocol drew on two years of experience with location-based virtual presence systems.2
But it never made it past the draft stage. It was never adopted as an RFC. The protocol died, but IANA kept the port assignment.
Why This Port Still Matters
Port 677 sits in the well-known ports range (0-1023), which means IANA officially assigned it. These ports are reserved for services that were supposed to become standard parts of Internet infrastructure.
Most well-known ports succeeded. Port 80 carries HTTP. Port 443 carries HTTPS. Port 25 carries email. Port 677 carries nothing—or at least, nothing related to Virtual Presence Protocol anymore.
This raises a real question: what happens to assigned ports when the protocol dies? IANA doesn't typically reclaim them. The assignment remains. The port becomes a fossil—evidence that someone once tried to build something here.
What Might Be Using It Now
Because VPP never took off, port 677 is functionally available for unofficial use. Any application could listen on this port for its own purposes. There's no widespread service that's claimed it as an unofficial standard (like how port 8080 became the unofficial alternative to port 80).
If you find something listening on port 677 on your network, it's not VPP. It's something else that happened to choose this port.
How to Check What's Listening
On Linux or macOS:
On Windows:
If you see something, investigate what process owns it. It won't be Virtual Presence Protocol.
The Larger Pattern
The well-known ports range is full of these ghosts. Protocols that seemed like good ideas at the time. Assignments made with optimism that the service would become standard infrastructure. And then the service failed to launch, or was replaced by something better, or solved a problem that stopped mattering.
Port 677 is a reminder that protocol design is as much about timing as technical merit. VPP tried to create social browsing before the web was ready for it. A decade later, services like Google Wave tried similar ideas. They failed too.
Maybe the problem is genuinely hard. Or maybe we just don't actually want to know who else is reading the same page we are. Sometimes isolation is the feature, not the bug.
The Virtual Neighborhood That Never Existed
In 1999, someone imagined a web where you weren't alone. Where you could sense other people nearby in document space. Where hyperlinks created neighborhoods and presence created community.
They got as far as a draft specification and a port assignment. The port remains. The neighborhood doesn't.
Port 677 is still waiting for its virtual neighbors. They're never coming.
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