PTCL + linked router connects to devices but internet doesn't work after connecting

[R1CK]

In my house I have connected 1 PC, 2-3 smartphones, and 1 tab through a PTCL router Sagemcom Fast 1704 and a TP-LINK router. It's a big house so depending on where you are you connect to either one of the device. The TP-Link router is connected to the PTCL one through an ethernet cable, and they both have different addresses. The problem I face is that plenty of times I want to connect to either one of the routers, any said device would connect, but the internet wont respond. To get it to work on one specific device involves a series of restarts on the router and/or the device, and that doesn't work all the time. Sometimes I'd get this issue on my PC too, in which case I'd flush the DNS cache, and that somehow works but I cant do that on my phones or tab and that isn't a concrete solution anyway. Can someone please tell me what's going and help me with this?

 

[abobobilly]

[MENTION=1191]R1CK[/MENTION]! By default, your modem will choose PTCL DNS which sometimes doesn't respond. You can solve your issue two ways:
1. By adding Google or any other (116.71.241.216) DNS to your Modem (PTCL one)
2. By adding Google or any other DNS to your devices individually.

That said, the 2nd Wireless Modem (or Router) you are using with PTCL, make sure you have created DHCP servers in both and have assigned specific IPs for specific devices.

 

[R1CK]

It seems to have had worked. However coincidentally at the same time, PTCL faced a 'backhand' issue that coincided with this so I cant tell for sure. I hope they'll fix it by tomorrow. Then I'd be able to tell for sure.