GL-B3000 (Marble) NAT hairpin/loopback troubles

Routers
1

(Firmware Version 4.5.22 - openwrt-b3000-4.5.22-0407-1744021171.img)

Configured is a port forward from a external port (WAN) to an internal server with internal port (LAN).

The access works from devices in then internet.

But when I try to access this internal server from a internal wired attached device via internet external IP, then it does not work.

It works isntantly whn I disable qca-nss-ecm
/etc/init.d/qca-nss-ecm stop

It seems, it is the same issue as here: GL-AX1800 (Flint) NAT hairpin/loopback troubles

It would be perfect, if that is solved out of the box in a patched firmware version.

Flint 3 - Downstream router issue
3

Hi,
Please upgrade to V4.7.2beta and test again.
https://dl.gl-inet.com/router/b3000/beta

4

Hi,
after upgrade to V4.7.2beta and fresh configuration from the scratch the NAT hairpin issue was visible again.
This means - the upgrade does not help.

It works again also with V4.7.2beta only when I disable qca-nss-ecm
/etc/init.d/qca-nss-ecm stop

So a new patched version is necessary.

5

Do You have any news for me?

6

Thanks for your update, we need to look into this issue

7

We really don't have the conditions to reproduce your problem. If possible, can you provide a computer and router remote control?

9

Thanks! This solved my issue on the GL-BE9300, but not sure the impact on my router.

To reproduce the issue, setup a HomeAssistant server with Public access with custom domain (duckdns), then from a downstream router, try accessing the public domain name. It works from internet and LAN clients, but not from a downstream router.

Traffic Path: Client[Web Browser] → :443 → BE9300 Router [Port Forwarding] → :8123

Hope this help!