[SOLVED] My new modem/router from ISP doesn't like any wireless router...

[supo]

Hi all, ever since I got this new Sagemcom Fast 3890V3 modem/router combo from my ISP 2 months ago I have a particular issue that I cannot solve no matter what I tried. The issue is that no matter which extra wireless router I connect to it my internet connection slows down to a crawl after 1-2 days randomly and becomes unusable. I have tried Asus ac86u, ac66u and Netgear Nighthawk XR500. I have zero problems with my line itself.

To solve the issue temporarily for 1-2 days again, all I need to do is to unplug the ethernet cable from the back of the modem/router and plug it right back in again, after that it works again without issues for 1-2 days.. I have changed all my cables with new ones just to be sure, and also changed my modem with another one though same model.

I put my Sagemcom into bridge mode so that I don't get double NAT and remove it's router functionalities.. Do I need to do something else before enabling bridge mode? Shouldn't it be enough to just enable that? There is conflict going on for sure but I cannot isolate it.

Really need help.

 

[kanewolf]

Is it WIFI only performance issues or wired also?

Your Asus routers have the capability to ping from the router. When it is unusable, what does a ping to 8.8.8.8 show? Packet loss? Unreachable?
Your Asus routers also have pretty good syslogs. What does the log say?

 

[supo]

Is it WIFI only performance issues or wired also?

Your Asus routers have the capability to ping from the router. When it is unusable, what does a ping to 8.8.8.8 show? Packet loss? Unreachable?
Your Asus routers also have pretty good syslogs. What does the log say?

No the issue is with both wired and wireless so the whole connection goes down so to speak. If I only use my ISP's modem/router alone by itself then no problem occurs no matter how many days pass, but when I want to use any external wireless router then the connection becomes bad after 1-3 days but not right away though. There must be something that needs to be done with the settings somewhere on the ISP's modem/router when connected to an external router because this problem sounds like a conflict is going after a while between the two of them. But I cannot figure it out for the life of me.

 

[kanewolf]

No the issue is with both wired and wireless so the whole connection goes down so to speak. If I only use my ISP's modem/router alone by itself then no problem occurs no matter how many days pass, but when I want to use any external wireless router then the connection becomes bad after 1-3 days but not right away though. There must be something that needs to be done with the settings somewhere on the ISP's modem/router when connected to an external router because this problem sounds like a conflict is going after a while between the two of them. But I cannot figure it out for the life of me.

It is unlikely. If you have the ISP device in bridge mode it really doesn't do anything. Since you are using it as just a modem, why don't you ask your ISP for a modem only device? It looks like a cable modem, so there should be modem only devices available that you can use.