Port 6379: Redis

What is port 6379 used for?

Caching and queues.

Is it safe to expose port 6379 to the internet?

Redis has no authentication by default. An open Redis is routinely taken over. Bind to localhost or a private network.

If port 6379 seems closed or unreachable

1. Check that the Redis service is running and listening on port 6379, not only on 127.0.0.1.
2. Check the firewall on the host itself (Windows Defender Firewall, iptables, nftables, ufw) for a rule that allows TCP 6379.
3. If the host is behind a router, confirm the forwarding rule points to the correct internal address and that your internet provider does not use carrier-grade NAT.
4. Test from outside your own network. A port can be open locally and blocked at the edge, or the other way round.

Using port 6379 safely

Treat port 6379 as an internal-only service. Reach it through a VPN or an SSH tunnel, restrict it by source address, and keep the software that listens on it patched.