Discussion Which is a better option, an access point or two routers

[hw_user]

I have 6 wired users and 10 wireless users. Two of the wireless users are 2.4G only. I am using a CGN3 modem+router from my ISP. I am getting a very weak WIFI signal at the far end of my house and I need more wired ethernet ports. All the users just need fast internet access and fast data transfer between devices is not a requirement. To add ethernet ports and to cover to WIFI blind spot, I need a new router. I bought a TP link AX55 router for WIFI 6 future proof (only 2 wireless users have WIFI 6) and I believe it must have better router performance than CGN3.
I have three setup options in mind
Option 1. Continue to use the CGN3 as the main router (DHCP provider). I will use an ethernet cable to connect between the LAN port of the AX55 and the LAN port of the CGN3. The AX55 will have DHCP disabled. Not sure if this setting is called a bridge or access point. Both the CGN3 and the AX55 have 3 ethernet ports left. This meets my requirements of 6 wired users and the AX55 should cover my WIFI blind spot. But I am not sure if I am taking any advantage of the AX55 performance.
Option 2. Continue to use the CGN3 as the main router. I will use an ethernet cable to connect between the WAN port of the AX55 and the LAN port of the CGN3. Now I am setting up the AX55 as a full router. I now have 2 networks, 192.168.0.x hosted by CGN3 and 192.168.1.x hosted by AX55 connecting to a single Modem. I have 3 ethernet ports on CGN3 and 4 ethernet ports on AX55 (one extra ethernet port). I assume that devices connected to the AX55 may be able to benefit from the better performance of the AX55. I know that devices on the two networks may have problems talking to each other. But direct data transfer between devices is not a requirement.
Option 3. Set up the CGN3 as a gateway only. I will use an ethernet cable to connect between the WAN port of the AX55 and the LAN port of the CGN3. The AX55 is set up as a full router. I hope this will exploit any performance enhancement of the AX55 over the CGN3. But I am losing 3 ethernet ports on CGN3. I only have the 4 ports on AX55 and I still have the WIFI blind spot. I have an old TPlink Archer C50 kicking around which I can set up as an access point (or bridge) to cover the WIFI blind spot and provide me with the additional ethernet port.
Please help me to decide which is a better option. New options are also welcome.

 

[bill001g]

What "performance enhancement" do you think the ax55 has over the cgn3.

Although it is no longer separate chips what you have inside a router is a small switch. This connects to the lan ports, the router chip,and the wifi chips.

The router chip only affects traffic between the switch and the wan port. Traffic going between the lan ports and even the wifi to the lan does not go though the router chip. In addition there is a hardware function that allows the traffic going lan/wan to bypass the router chip. This is a hardware nat assist function almost every router now has.

Pretty much the only time the router processor itself looks at the data is if you are using say firewall function or some other kind of traffic filtering. You really don't want to use these feature if you have a high speed internet...like over 300mbps. The cpu speed will cap the data rate.

The first method you suggest is how you make any router into a AP. The traffic never passes wan/lan so the router cpu is not used. Most routers also have a feature that set the router into ap/bridge mode. All this really does is move the wan port to the switch chip/function bypassing the router chip.

You seem to know why you do not run router behind router.

In effect using a router as a AP just adds more ethernet ports to the main router and adds more wifi radios to the main router....that just happen to be in a remote location.

All wifi functions are done by the wifi chips themselves. They are in small cpu that get their firmware loaded by the main router chip. This firmware most times comes from the chipset vendor, most router manufactures do not modify it to avoid issues with the FCC.

Many years ago you could change what was loaded into the wifi chips on third part firmware. Because people changed stuff like transmit power the FCC cracked down and now you only get the binaries from the chipset vendor and all the wifi function is locked up inside the wifi chip cpu where you can't change much.