Flint 2 (GL-MT6000) Becomes Unreachable When PPPoE Connection Fails

Technical Support for Routers
1

Hi everyone,

I’m experiencing a strange issue with my Flint 2 (GL-MT6000) running firmware 4.7.0 when using a PPPoE connection.

Issue Description:

  • When I connect my Flint 2 to a PPPoE ONT that does not have an active internet connection, the router becomes completely unreachable.
    I can't access the web interface, SSH, or even ping it.

  • However, if I unplug the WAN cable, the router immediately becomes accessible again.

  • If I restore the router to factory settings and try the same setup, the router remains accessible even without PPPoE working.

  • Right now, I’m using a WiFi backup connection, and everything is working fine.

  • Is this a firmware bug or a misconfiguration?

  • Why does the router become unreachable only after setting up PPPoE but remains accessible in factory settings?

  • Could this be related to a DHCP or network routing issue when PPPoE is not established?

Has anyone else encountered this problem? Any ideas on how to prevent this from happening?

My FW version is 4.7.0.

Thanks in advance for your help!

2

Can I ask? when you mention "reachable" or "accessible", where are you trying to reach or access router from? Are you meaning remotely accessing it via WAN or are you trying to access it from within its own LAN? My connection is PPPoE and I have never encountered this problem.

3

Hi, it is completely unreachable via LAN.
It is unreachable via WAN too but it’s not connected to the Internet, so it is normal.
Note that if the PPPoE is working, everything works fine on my router too. The problem is when PPPoE connection is not working.
I think that maybe my ONT sends a “strange” packet that hangs my router.
Or something similar…

4

Does your ont all green lights? If your are Vodafone UK broadband. Depend Vodafone UK broadband has two different cables - Cityfibre and Openreach .

5

this sound very weird, usually a wan connection or fail should not cause the lan network to fail.

The only reason i could manage to replicate something like this is if it is a ip subnet conflict, does your guest network work via wifi when this happen?

6

I'm not in UK, anyway it is all green, but my provider does not allow me to use that ONT, this is why it does not work.

7

Your WAN IP is public ? Or your WAN IP looks like wire guard IP ranges? 10.0.x.x like conflict IP ranges.
Overall problem is you provider side. Could be laser cable condition is bad or bad weather somewhere...

8

Hi, I had the same idea, so I changed my LAN from 192.168.100.0/24 to 192.168.90.0/24.
Same problem.
My ONT is a Nokia with 192.168.100.1 IP address.

9

My WAN IP is public. I’ll try changing the cable but it should not work at all even with a Factory reset. As I mention before, if I factory reset my Flint, everything works fine even without a working Internet connection.

10

I literally posted the same issue on a flint i bought yesterday.

internet goes down, cant access any network device.

removed all cables and reset factory then downgraded to 4.6.6 , solved for now.
waiting for more clarifications, my Op is 21.02

11

hmm which firmware do you use currently?

I'm guessing there is a issue with 2.5G negotiation on the MTK firmware hence why it fails.

op24 has newer drivers, but it is already older than OpenWrt themselves (I believe it was forked at 24.10 RC2 that is older) you may aswell use the latest 24.10.0 release version of Openwrt directly :wink:

12

It is OpenWrt 21.02-SNAPSHOT r15812+1082-46b6ee7ffc / LuCI openwrt-21.02 branch git-22.335.71649-0ecaf74
You are missing the focal point, I think.
If I perform a full reset, I do not have issues even with a PPPoE connection not active.
This must be related to some misconfiguration or similar and I cannot find it in any configuration file.