GT-AX11000 can't get WAN IP with newer firmware

[vasittu]

Setup: optic fiber connection with ISP's fiber box connected to the GT-AX11000 WAN-port.

I have a WAN IP problem with Asus GT-AX11000 and my fibre connection. The GT-AX11000 works with the following firmware "GT-AX11000_3004_388.5_0_rog_ubi" but as soon as I update a newer one, the "GT-AX11000_3004_388.6_0_rog_ubi" or the newest "GT-AX11000_3004_388.9_2_rog_ubi" for example, the router can't get WAN IP address. As for Asus official firmware, "3.0.0.4.388_23285" is the newest that works and it was released on 15.05.2023.

The following steps have been tested:

• Changed the DHCP query frequency
  • With firmware version 3.0.0.4.388_23285, both normal and aggressive modes work (did not test continuous mode)
  • With newer versions (e.g., 3.0.0.4.388_24403), tried normal, aggressive, and continuous modes — none of them work
• Connected a laptop directly via cable to the optic fiber box/modem — it receives an IP address and the internet works
  • Cloned the laptop’s MAC address to the router — router still does not get a WAN IP
• Powered off both the fiber modem and the router for 30 minutes to allow the DHCP lease to expire. Here in Finland Telia (ISP) has a ridiculously short lease time.
  • Powered the fiber modem back on first and waited until it was fully operational (all lights on), then restarted the router
  • The router still does not receive a WAN IP address after all of this

The issue is likely due to DHCP incompatibility between the router’s new firmware and Telia? Could there be a bug in Asus’s firmware that prevents Telia’s DHCP server from accepting the DHCP DISCOVER / REQUEST messages? Have there been any changes made to DHCP queries/handling in the newer Asus firmware versions?

In short, router works with 3.0.0.4.388_23285 or Merlin GT-AX11000_3004_388.5_0_rog_ubi. Doesn't work with any newer firmwares, No WAN IP. Works immediately when downgrading to prevously mentioned firmwares.

Any tips or knowledge about the changes in the routers DHCP handling?

Here are the current WAN-settings, which work flawlessly with the GT-AX11000_3004_388.5_0_rog_ubi but not the newer ones.

 

[Ripshod]

I see no mention of a reset. Have you attempted one?

 

[vasittu]

I have before, like 8 months ago and I just tried again to be sure. Here's what I did. Had a working FW 3004_388.5_0_rog installed --> performed factory reset --> works after factory reset, router gets WAN IP. Updated to 3004_388.6_0_rog --> doesn't work, no WAN IP. Also updated to the 3004_388.9_2_rog with factory settings --> no WAN IP, doesn't work either. Reverted back to the 3004_388.5_0_rog with the same factory settings --> router instantly gets WAN IP, everything works. After that I uploaded the settings backup.

The DHCP query frequency setting was aggressive in factory settings, I tried also the normal with 3004_388.6_0_rog and 3004_388.9_2_rog with everything else as factory settings.

 

[Grumpy_Geoff]

The DHCP query frequency setting was aggressive in factory settings

Have you tried 'continuous' DHCP Query Frequency?

Edit -
Yes you have:
'With newer versions (e.g., 3.0.0.4.388_24403), tried normal, aggressive, and continuous modes — none of them work'

 

[vasittu]

Yes correct, but I realized that I haven't actually tried it with everything else as factory settings. So just tested it. Hard reset to factory settings with a working FW 3004_388.5_0_rog --> DHCP query mode was aggressive by default --> received WAN IP --> changed query mode to continuous --> also got WAN IP. Updated FW to 3004_388.6_0_rog --> doesn't work, no WAN IP with continuous mode.

EDIT. Noticed that with non-working FW 3004_388.6_0_rog and no WAN IP, one of the router CPU cores is almost maxed to 100%, it's constantly over 95%. Also the router settings interface is extremely slow to use. It doesn't load the settings pages, I need to close and retry several times to get to the page I need.

 

[degrub]

Are you manually configuring the WAN settings after factory reset or using a saved config file ?

 

[Jeffrey Young]

What does the system logs say about it?