Zyxel T50 firmware - issue with DHCP/DNS

  • 11 januari 2021
  • 6 reacties
  • 305 Bekeken

Whenever I am trying to work on using a DHCP or DNS server in my network other than my router’s inbuilt one, I am ending up with a no-Internet network. The only way out is to reset the router and redo the settings, including setting it to the built-in DHCP/DNS - which I am not satisfied.

Any ideas regarding how this can be corrected? Am I missing anything?

T-mobile support, I would like to discuss this in more details if you can assist with it.

6 reacties

Reputatie 7
Badge +19

Hello @rebellious 

For DNS go to thuisnetwerk > LAN configuratie > under DNS waarden check statische DNS and fill in and (Google) for example, click toepassen and restart your modem.

What exactly do you want to change in the DHCP settings?

When changing the LAN IP to the DHCP pool should change automatically I guess if not adjust manually, click toepassen and restart your modem.

My problem is that whenever I try changing this to custom settings (which does not work either) and revert everything back, the Internet connectivity does not restore until the router undergoes factory reset.

In brief, I know what I am doing. The ultimate goal is to use Pi-hole for DNS/DHCP handling. But T50 sucks at handling the forwarding and then in turn sucks at bringing the normal initial config to the working state.

In fact, I have found a similar topic posted here a year ago. Same symptoms when performing same operations. This means that through several releases of router firmware this bug has not been fixed.

By the way, in that other thread the OP was advised to use the router as DHCP server, which is not my intention as per my use case. 


Reputatie 4
Badge +2

Hi @rebellious ,

Thanks for your message! Am I correct in assuming that the topic you’re referring to is this topic (link is clickable)? Maybe our hero @yalerta can dust of his cape again and give you some pointers! 

Yes, your assumption is correct regarding the topic.

I don't think @yalerta will be of really much help here, as it's about malfunctioning of the firmware rather than some config issue. I would probably need a T-mobile tech to look into it.



I had the same with the t50 modem, I put a router i bought myself behind it and took back control of my own home network. 
If I change anything in the settings then you just have no internet at all, even if you let the DHCP relay server output the same as the T50 modes, then you still have no internet connection. 
I had no problems with this at all with previous providers (kpn,ziggo,tele2) 











Zyxel firmware laat Inderdaad veel te wensen over… eerste tegenvallen na 10 minuten aangesloten te zijn…
Interface loopt vast, voortijdige reboot, er ontbreekt veel… meteen maar een ander modem bestellen, dat zou moeten kunnen werken... 

Dacht dat dit soort praktijken inmiddels passé waren… zucht.