@Martin_S i tried implementing the secondary IP as mentioned but it takes Internet down on my LAN side although WAN stays up. Sounds like its trying use use the secondary IP connection as the default...

@Martin_S Maybe worth looking at this thread https://community.tp-link.com/en/business/forum/topic/594038 Whilst its related to an ER605 , I suspect the ER7206 is similar.

@AnnusKhan Currently, the maximum number of clients connected to the network is 345 The default DHCP pool will only provide 253 IP addresses. Whilst I guess you don't have all 345 clients connected...

@Hobbit76 SIP requires a domain That's a new one on me. Is it just a requirement of SIP on the Fritzbox ? At least you have it working now

My understanding of that is, when you configure your LAN, you should provide a DHCP range that is smaller than your network. Then make an IP reservation for IP addresses from outside of your DHCP...

@Hobbit76 The Fritzbox does not require a /24 network. It's just supposed to be a transfer network. She only has one device, the router. A /30 network without DHCP should also be enough, but I also...