Port 6379 Redis – Free, Online, Private

What listens on 6379

Port 6379 is Redis. The IANA name is redis. The registry description is an advanced key-value cache and store, assigned in 2015. The client protocol is RESP over TCP. TLS is not the default. When it is enabled it is usually the same port with a tls-port setting, or a second port you chose. There is no separate IANA number for Redis TLS. UDP 6379 is reserved. Redis Cluster uses a second port, the data port plus 10000, so 16379, for the cluster bus. That bus is not the client port. A managed Redis still speaks this protocol. The hostname changes. The number often does not.

The IANA service name is redis: An advanced key-value cache and store. The practical transport is TCP. The checks below use TCP. IANA may also have a UDP row for 6379. The service described here is the TCP one. A process can bind this port without being the service in the registry. The commands show who bound it. They do not prove the protocol on the wire is the one IANA named.

Service notes for port 6379

Service notes for port 6379: the IANA name is redis (An advanced key-value cache and store), and the program people mean is Redis. TCP 6379 is the IANA redis port. Redis speaks RESP on that socket. UDP 6379 is reserved. A default install often has no authentication. Redis with protected-mode off and no requirepass, bound to a public address, is a remote command channel. It has been used to plant keys and to write files. Bind it to the application network, turn protected mode on, set a password or an ACL user, and rename or disable CONFIG, FLUSHALL, and DEBUG for clients that do not need them. Replication and the cluster bus are more ports and more trust. Do not put the primary on the internet and call the password a security boundary. Use TLS if the path is shared. Nothing in that paragraph applies to a different number just because the software family is similar. If your listener is not on 6379, you are on the wrong page.

A connection refused from the app and a listener on 127.0.0.1 is the default bind working. Another trap is a security group that allows 6379 and a cluster that also needs 16379 between nodes. Clients work, resharding fails. Another is AUTH sent to a server that has no password, which errors, or not sent to a server that does. Another is a replica that is reachable and read-only, so writes fail and the port is blamed. Another is IPv6. bind 127.0.0.1 does not bind ::1 unless you say so.

How to check whether it is open

On the machine itself, ask the kernel which socket is bound. ss and lsof do that. A firewall, a security group, and a Docker publish rule sit in front of that socket, so a listener is not the same thing as a port the internet can use. From somewhere else, nc -vz host 6379 tries a TCP handshake when the command is the TCP form. A refusal means something answered with a reset. A timeout means a filter dropped the packet or the host is unreachable. Those are different faults. redis-server should own TCP 6379. A public 0.0.0.0 with protected-mode no is the finding to fix. redis-cli ping from the app host is the test. PONG means the protocol answered. It does not mean the ACL allows the command you care about.

grep and findstr match text. A pattern of :80 also matches :8080 and :8000. The lsof and Get-NetTCPConnection forms take a numeric port and do not have that substring bug. Use them when the number is ambiguous. ss filters in the kernel with sport = :N, which is also exact. On macOS, netstat -p selects a protocol. It does not print the process the way Linux netstat -p does. lsof prints the process.

• UDP 6379 is reserved. Clients use TCP.
• The cluster bus is 16379 by default, not 6379.
• No password and a public bind is a remote shell in practice.
• A replica accepts the TCP connection and rejects writes.

Linuxsudo ss -lptn 'sport = :6379'
sudo lsof -nP -iTCP:6379 -sTCP:LISTEN

macOSsudo lsof -nP -iTCP:6379 -sTCP:LISTEN
netstat -anv -p tcp | grep '\.6379[^0-9]'

Windowsnetstat -ano | findstr :6379
Get-NetTCPConnection -LocalPort 6379

Remotenc -vz host 6379