For o2 my Home cable connections, compatible provider-independent devices from the retail stores as well as the rental devices from o2 can be used. Devices from other providers cannot be used. 

You can find the interface description here:
https://www.telefonica.de/impressum/schnittstellenbeschreibungen-der-betreiber-oeffentlicher-telekommunikationsnetze-nach-41c-tkg.html

Used retail units that are still registered for another user cannot be used either. Since this is not apparent before buying a second-hand device, I would generally advise against buying a second-hand cable modem router. Otherwise you will have bought a useless device. 

A provider branded router will not be added to the system. Normally you are not able to see the Mac on the cable interface.

You could use the following AVM Cable router:

• FRITZ!Box 6690 Cable mit AVM Artikelnummer 20002965
• FRITZ!Box 6660 Cable mit AVM Artikelnummer 20002910
• FRITZ!Box 6591 Cable mit AVM Artikelnummer 20002857

Hello @Saugat ,

welcome to the o2 Community .

There could be two components at work here that stop the router that you are using from being able to provide you with a connection, the first and biggest one blablup and schleuj already explained. If the router is already registered at a provider then it can’t be used for this connection. The other one is that it is apparently an older device and as such might not meet the DOCSIS 3.1 standard that we ask for. There were already a few models suggested here by schluej, you can of course also rent a router directly from o2.

Kind regards, Sven

Thank you for the information. But after i got a new router and provided the new mac address its taking long and they have opened multiple tickets for changing the mac address but i have been waiting since 5 days. Every time they have been making a new ticket. Does it take so long to change the mac address when someone changes the router. 

You could change the CM-MAC in Mein O2.

Is it a new Router?

What kind of router did you buy?

Fritzbox 6660.i couldn't change it myself asked the o2 service multiple time and each time they ask same but not changed yet. 

Hello, my Internet connection was started on 2nd of may and during that time i used an old unity media router which didn't worked out so i bought a new fritzbox 6660 and provided the mac address to the technician over the phone multiple time. Neither the mac address is changed nor the Internet is working. How should i proceed further. I am looking for urgent help to make my internet working.

Thank you. 

Edit o2_Sven 12.05.2023/08:40: Merged threads

Hello @Saugat ,

from what I can see a change of the MAC-Address has occured yesterday. Is your connection up and running now or are there still issues?

Kind regards, Sven

Hi @Saugat,

we would still appreciate feedback from you and we hope that it's working now. 

Best regards, Marco