Signal strength fluctuations and performance issues with cascading routers

Question

I am using two home routers (Linksys WRT300N and Netgear Nighthawk AC1900)in cascade order to extend the area covered by WIFI. The signal strength and performance of the network throughout the home is very hit or miss, however. The router seems to either work completely or not at all.

I have disabled DHCP settings for the second router, which is plugged into the first. I suspect that this is a transmission band overlap problem, but I don't know how I should solve it. Any ideas?

Answer 1

"Cascading" is a non-standard term, so if you find few questions with that in them, it's not a surprise. Using multiple routers (per below, most being used as APs, one as router and AP ), is dirt common.

Very likley you have interference between the Access Points (for the sake of my sanity, if not yours, let's call the "part that provides WiFi" the Access Point and the "part that connects to your WAN connection and handles DHCP & NAT" the router, even if they are in a single box.)

So you are using one router with access point, and a second "router" but as an access point. The one acting only as an access point should have nothing plugged into it's WAN port unless it can be put into an AP-Only mode where WAN and LAN are bridged. It should be assigned an address on the LAN of the router and be plugged into the LAN of the router - and it should know that the router is its gateway (and likely also DNS and NTP.)

That covers the wired side of things.

On the wireless side of things, especially at 2.4 GHz, there's a wealth of misunderstanding which is helped by some idiotic conventions. Depending where you are in the world, there are 11 (or 13) channels in th 2.4 GHz band. However, they are not adequately spaced, so there REALLY are only 3 usable ones (from 11) or possibly 4 (from 13.)

In the US, it's 11, and the usable (non-overlapping) channels are 1, 6, and 11. However, if you are running 40 MHz rather than 20 MHz you actually use 2 channels - 1&6, 6&11 - so two APs with any overlap that are running 40 MHz channels are going to interfere, even if they are on "different" channels.

The other common problem is assuming (as most people do) that cranking up the transmit power will make everything better. Which is sort-of true if you include interference as part of "everything", and false otherwise.

Now, folks get all in love with the idea that maximum channel width is going to make things faster - but if you can't connect, or only very poorly, due to interference, that's just not so. So try 20 MHz channel width (for the 2.4 MHz band) and make sure that your APs are transmitting on different channels (with 2, I'd suggest 1 & 11 unless you run a channel scan that shows a lot of outside signal on one of those frequencies)

A pretty good question and answer regarding 1, 6, 11:

Is it better to use a crowded 2.4GHz Wi-Fi channel 1, 6, 11 or "unused" 3, 4, 8, or 9?

The other thing you may find is that your house construction may simply be hostile to WiFi signal propagation. Wood and drywall is not too bad, normally; metal or concrete is very bad indeed. Even a large number of wood and drywall walls between the AP and your device will degrade the signal, and usually the signal that's lost first is the one from your device to the AP.