210
z3950
TCP · 0x00D2
Port 210 — z3950
Others
Port 210 carries Z39.50 library search over TCP. Being at or below 1023, only root may open it on Unix.
0–1023. On Unix only root may open one.
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
- Z39.50 library search (z3950)
- Kind
- Others
- Protocol
- TCP
- Range
- Well-known
- Root needed
- Yes
- Hexadecimal
- 0x00D2
- Binary
- 0000000011010010
- Two bytes
- 0 · 210
Same kind
Time, printing, play — the ones that fit nowhere else.
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 210 used for?
Z39.50 library search (z3950) uses it, over TCP.
Q. Does opening port 210 need root?
Yes. It is at or below 1023, so on Unix only root may open it.
Q. Which range does port 210 fall in?
Well-known (0–1023). In hex it is 0x00D2.
Q. Does port 210 have a twin?
Not a separate one. It either was encrypted from the start or negotiates TLS on the same number.