2181
zookeeper
TCP · 0x0885
Port 2181 — zookeeper
Dev and ops
Port 2181 carries Apache ZooKeeper 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
- Apache ZooKeeper (zookeeper)
- Kind
- Dev and ops
- Protocol
- TCP
- Range
- Registered
- Root needed
- No
- Hexadecimal
- 0x0885
- Binary
- 0000100010000101
- Two bytes
- 8 · 133
Same kind
Ports that development and operations tools open.
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 2181 used for?
Apache ZooKeeper (zookeeper) uses it, over TCP.
Q. Does opening port 2181 need root?
No. It is above 1023, so an ordinary user can open it.
Q. Which range does port 2181 fall in?
Registered (1024–49151). In hex it is 0x0885.
Q. Does port 2181 have a twin?
Not a separate one. It either was encrypted from the start or negotiates TLS on the same number.