Port 5670 ZRE-DISC
Port 5670 has a different IANA assignment for each transport protocol: TCP filemq; UDP zre-disc.
What is port 5670 used for?
Port 5670 carries a different IANA service on each transport protocol: TCP filemq; UDP zre-disc. It sits in the registered range, the block used by databases, application servers and developer tooling. Port conflicts here are common when several local services start at once. The same port is also registered under filemq.
Each transport reaches a different service on this number, so match the protocol to the service you are diagnosing. A TCP check says nothing about a UDP listener on the same port, and the reverse is also true. Both transports still bind to the same number, which is why two processes can collide even when they use different protocols.
Use the commands below to confirm whether port 5670 is actually in use before you change firewall rules. Blocking the port stops new inbound traffic at the firewall, but it does not stop a local process from listening, and it does not remove the service from the machine.
Browse all Message queues and streaming ports
Source: IANA Service Name and Transport Protocol Port Number Registry. Registered assignee: [Pieter_Hintjens_3].
Check and block port 5670
Copy-ready commands for the protocols assigned to this port. Run the check first, then block only what should not be reachable.
Check on Linux
sudo ss -tlpn 'sport = :5670'
sudo ss -ulpn 'sport = :5670'Check on Windows
Get-NetTCPConnection -LocalPort 5670 -State Listen -ErrorAction SilentlyContinue
Get-NetUDPEndpoint -LocalPort 5670 -ErrorAction SilentlyContinueBlock with UFW
sudo ufw deny 5670/tcp
sudo ufw deny 5670/udpBlock with iptables
sudo iptables -A INPUT -p tcp --dport 5670 -j DROP
sudo iptables -A INPUT -p udp --dport 5670 -j DROPThese commands are examples for a typical host. Check the listener before you change firewall rules, and persist iptables rules with iptables-save or netfilter-persistent. On Windows, use Windows Defender Firewall or New-NetFirewallRule for persistent blocks. The iptables rules here cover IPv4; mirror them with ip6tables if IPv6 is enabled.
Is port 5670 safe to expose?
This port is not on our curated list of services with a widely exploited profile. Exposure is only safe when the listening service is intended, patched and protected by a firewall. Keep the listening service patched and remove it if unused. A default-deny firewall policy with explicit allow rules is still the safest baseline.
Where port 5670 is usually used
Most traffic on port 5670 falls into these scenarios. The demo below is a safe way to confirm the listener before you change anything.
- Producers publishing events and consumers subscribing to topics or queues.
- Microservices decoupling background work through a broker on port 5670.
- Local development brokers running in Docker with a published port.
Probe the broker
A TCP probe confirms the listener before you chase authentication or topic errors.
nc -vz 127.0.0.1 5670Common problems with port 5670
Connection refused or timed out
Refused usually means the host is reachable but nothing is listening on port 5670. A timeout more often means a firewall drop, a wrong host or a service bound to a different interface.
Port already in use
Find the process holding the port with sudo ss -tlpn 'sport = :5670' or sudo lsof -i :5670. Stop that process or configure it to bind another port; killing it without identifying it can take down a production service.
Firewall rule did not survive a reboot
UFW and Windows Firewall keep rules across restarts. Raw iptables rules do not: save them with iptables-save or the netfilter-persistent package, and re-apply after upgrades that reset the ruleset.
The port is blocked but still reachable
A firewall rule filters inbound traffic; it does not close the listener. Confirm with the check command above and bind the service to 127.0.0.1 when only local clients need it.
Port 5670 at a glance
| Port number | 5670 |
|---|---|
| Service name | zre-disc |
| Aliases | filemq |
| Transport protocol | TCP / UDP |
| Assignments by protocol |
|
| Category | Message queues and streaming |
| Range | Registered port (1024–10000) |
| Risk level | Standard/Low |
| Registered assignee | [Pieter_Hintjens_3] |
| Registry description | Local area discovery and messaging over ZeroMQ |
| Source | IANA Service Name and Transport Protocol Port Number Registry |
Frequently asked questions
What is port 5670 used for?
Port 5670 (ZRE-DISC). The IANA registry assigns a different service on each transport protocol: TCP filemq; UDP zre-disc.
How do I check if port 5670 is open?
On Linux run `sudo ss -tlpn 'sport = :5670'` and `sudo ss -ulpn 'sport = :5670'`. On Windows run `Get-NetTCPConnection -LocalPort 5670 -State Listen -ErrorAction SilentlyContinue` and `Get-NetUDPEndpoint -LocalPort 5670 -ErrorAction SilentlyContinue` in PowerShell. If the port is open, the output shows a process listening on port 5670; empty output usually means nothing is bound to it.
How do I block port 5670?
With UFW run `sudo ufw deny 5670/tcp` and `sudo ufw deny 5670/udp`. With iptables run `sudo iptables -A INPUT -p tcp --dport 5670 -j DROP` and `sudo iptables -A INPUT -p udp --dport 5670 -j DROP`. Persist the iptables rules with your distribution's netfilter-persistent or iptables-save tooling so they survive a reboot.
Is port 5670 safe to expose?
This port is not on our curated list of services with a widely exploited profile. Exposure is only safe when the listening service is intended, patched and protected by a firewall. Nevertheless, keep the listening service patched and remove it if unused. A default-deny firewall policy with explicit allow rules is still the safest baseline.
Related ports
Primary data: IANA Service Name and Transport Protocol Port Number Registry.
Last reviewed 2026-10-30 · Methodology · About · Privacy