389
ldap
TCP and UDP · 0x0185
Port 389 — ldap
Name lookup
Port 389 carries Directory access over TCP and UDP. Being at or below 1023, only root may open it on Unix. Its encrypted twin is 636.
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
- Directory access (ldap)
- Kind
- Name lookup
- Protocol
- TCP and UDP
- Range
- Well-known
- Root needed
- Yes
- Hexadecimal
- 0x0185
- Binary
- 0000000110000101
- Two bytes
- 1 · 133
- Encrypted twin
- 636
Same kind
Turning names into addresses, or looking people and machines up.
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 389 used for?
Directory access (ldap) uses it, over both TCP and UDP.
Q. Does opening port 389 need root?
Yes. It is at or below 1023, so on Unix only root may open it.
Q. Which range does port 389 fall in?
Well-known (0–1023). In hex it is 0x0185.
Q. Is there an encrypted version of port 389?
Port 636 does the same thing wrapped in TLS.