[GH-ISSUE #5257] TCP PROXY V2 doesn't work with IPv6 Addresses

gitea-mirror commented

2026-05-05 14:34:39 -06:00

Owner

Copy link

Originally created by @viperman1271 on GitHub (Mar 20, 2026).
Original GitHub issue: https://github.com/fatedier/frp/issues/5257

Bug Description

I'm trying to decode the remote IP address of the connecting clients. For ipv4, there are no issues. But for ipv6, it seems to forward the ipv4 address of the docker gateway 100% of the time.

frpc Version

0.67.0

frps Version

0.67.0

System Architecture

linux/amd64

Configurations

frpc.ini

[common]
server_addr = WITHHELD
server_port = 7000
token = WITHHELD

[smtp]
type = tcp
local_ip = WITHHELD
local_port = 25
remote_port = 25
proxy_protocol_version = v2

frps.ini

[common]
bind_port = 7000
proxy_protocol_version = v2

dashboard_addr = 0.0.0.0
dashboard_port = 7500
dashboard_user = WITHHELD
dashboard_pwd = WITHHELD

token = WITHHELD

allow_ports = 25

Logs

Nothing in the logs describes the issue

Steps to reproduce

Configure according to frps.ini & frpc.ini on two different machines
Send yourself an email to the email server
Notice problem with decoding the real ip addresses

Affected area

Docs
Installation
Performance and Scalability
Security
User Experience
Test and Release
Developer Infrastructure
Client Plugin
Server Plugin
Extensions
Others

Originally created by @viperman1271 on GitHub (Mar 20, 2026). Original GitHub issue: https://github.com/fatedier/frp/issues/5257 ### Bug Description I'm trying to decode the remote IP address of the connecting clients. For ipv4, there are no issues. But for ipv6, it seems to forward the ipv4 address of the docker gateway 100% of the time. ### frpc Version 0.67.0 ### frps Version 0.67.0 ### System Architecture linux/amd64 ### Configurations #### **frpc.ini** [common] server_addr = **_WITHHELD_** server_port = 7000 token = _**WITHHELD**_ [smtp] type = tcp local_ip = _**WITHHELD**_ local_port = 25 remote_port = 25 proxy_protocol_version = v2 ### **frps.ini** [common] bind_port = 7000 proxy_protocol_version = v2 dashboard_addr = 0.0.0.0 dashboard_port = 7500 dashboard_user = _**WITHHELD**_ dashboard_pwd = _**WITHHELD**_ token = _**WITHHELD**_ allow_ports = 25 ### Logs Nothing in the logs describes the issue ### Steps to reproduce 1. Configure according to frps.ini & frpc.ini on two different machines 2. Send yourself an email to the email server 3. Notice problem with decoding the real ip addresses ### Affected area - [ ] Docs - [ ] Installation - [ ] Performance and Scalability - [ ] Security - [ ] User Experience - [ ] Test and Release - [ ] Developer Infrastructure - [ ] Client Plugin - [ ] Server Plugin - [ ] Extensions - [x] Others

gitea-mirror

2026-05-05 14:34:39 -06:00

closed this issue
added the
lifecycle/stale
label

gitea-mirror commented

2026-05-05 14:34:42 -06:00

Author

Owner

Copy link

@github-actions[bot] commented on GitHub (Apr 4, 2026):

Issues go stale after 14d of inactivity. Stale issues rot after an additional 3d of inactivity and eventually close.

@github-actions[bot] commented on GitHub (Apr 4, 2026): Issues go stale after 14d of inactivity. Stale issues rot after an additional 3d of inactivity and eventually close.

No Branch/Tag specified