[GH-ISSUE #2551] Can't use lower number port as remote port #2026

New issue

Closed

opened 2026-05-05 13:18:38 -06:00 by gitea-mirror · 3 comments

gitea-mirror commented

2026-05-05 13:18:38 -06:00

Owner

Originally created by @tmpuserx on GitHub (Aug 27, 2021).
Original GitHub issue: https://github.com/fatedier/frp/issues/2551

[REQUIRED] hat version of frp are you using

Version: frp_0.37.1_linux_amd64

[REQUIRED] What operating system and processor architecture are you using
OS: Ubuntu 20.04.2 LTS
CPU architecture: AMD64

[REQUIRED] description of errors
When I used ports lower than 1000 for remote_port and start frpc it's giving error start error: port unavailable. i can confirm that the port isn't in used on the system which running the frps

confile

[common]
server_addr = serverip
server_port = 7371

[laptop1rdp]
type = tcp
local_ip = 127.0.0.1
local_port = 3389
remote_port = 21

log file

Steps to reproduce the issue

in frpc.ini, the remote_port put something like 21, 23, 80, etc ports which not being used on frps server
run frpc -c frpc.ini

Supplementary information

Can you guess what caused this issue
those ports might be reserved for the official application such as ftp, telnet, http etc. but as long as there are not these services running on the server, they should need to be able to be used..

Checklist:

[] I included all information required in the sections above
[] I made sure there are no duplicates of this report (Use Search)

Originally created by @tmpuserx on GitHub (Aug 27, 2021). Original GitHub issue: https://github.com/fatedier/frp/issues/2551     **[REQUIRED] hat version of frp are you using**  Version: frp_0.37.1_linux_amd64 **[REQUIRED] What operating system and processor architecture are you using** OS: Ubuntu 20.04.2 LTS CPU architecture: AMD64 **[REQUIRED] description of errors** When I used ports lower than 1000 for remote_port and start frpc it's giving error start error: port unavailable. i can confirm that the port isn't in used on the system which running the frps **confile**  [common] server_addr = serverip server_port = 7371 [laptop1rdp] type = tcp local_ip = 127.0.0.1 local_port = 3389 remote_port = 21 **log file**  **Steps to reproduce the issue** 1. in frpc.ini, the remote_port put something like 21, 23, 80, etc ports which not being used on frps server 2. run frpc -c frpc.ini 3. **Supplementary information** **Can you guess what caused this issue** those ports might be reserved for the official application such as ftp, telnet, http etc. but as long as there are not these services running on the server, they should need to be able to be used.. **Checklist**:  - [] I included all information required in the sections above - [] I made sure there are no duplicates of this report [(Use Search)](https://github.com/fatedier/frp/issues?q=is%3Aissue)

gitea-mirror closed this issue

2026-05-05 13:18:39 -06:00

gitea-mirror commented

2026-05-05 13:18:40 -06:00

Author

Owner

@fatedier commented on GitHub (Aug 27, 2021):

Run frps as root user.

@fatedier commented on GitHub (Aug 27, 2021): Run frps as root user.

gitea-mirror commented

2026-05-05 13:18:42 -06:00

Author

Owner

@tmpuserx commented on GitHub (Aug 27, 2021):

that works! thanks!

@tmpuserx commented on GitHub (Aug 27, 2021): that works! thanks!

gitea-mirror commented

2026-05-05 13:18:42 -06:00

Author

Owner

@landuo commented on GitHub (Mar 14, 2022):

use default frps.service to start, can't use port 80, change 'User' to 'root' runs goods in frps.service.

@landuo commented on GitHub (Mar 14, 2022): > use default frps.service to start, can't use port 80, change 'User' to 'root' runs goods in frps.service.