1521
oracle
TCP · 0x05F1
Port 1521 — oracle
Databases
Port 1521 carries Oracle Database listener over TCP. Above 1023, so an ordinary user can open it.
1024–49151. Meant to be applied for, though some numbers here are custom by habit.
Where it sits in 65535
A port number is 16 bits, so it stops at 65535. The narrow band at the left is everything up to 1023.
065535
- Service
- Oracle Database listener (oracle)
- Kind
- Databases
- Protocol
- TCP
- Range
- Registered
- Root needed
- No
- Hexadecimal
- 0x05F1
- Binary
- 0000010111110001
- Two bytes
- 5 · 241
Same kind
Where a database waits for queries.
Ports next to it
How to read this
- A port number is 16 bits, so it runs 0 to 65535. There is no port 65536.
- Opening anything at or below 1023 needs root on Unix.
- Plain and encrypted often live on different numbers — 80 and 443, for one.
- Numbers like 3000 and 8080 were never registered; those are marked as custom.
Frequently asked questions
Q. What is port 1521 used for?
Oracle Database listener (oracle) uses it, over TCP.
Q. Does opening port 1521 need root?
No. It is above 1023, so an ordinary user can open it.
Q. Which range does port 1521 fall in?
Registered (1024–49151). In hex it is 0x05F1.
Q. Does port 1521 have a twin?
Not a separate one. It either was encrypted from the start or negotiates TLS on the same number.