Aaron B

The data you posted shows that your ISP modem/router is creating the following sub net
IPv4 addresses - 192.168.2.x (192.168.2.1 - 192.168.2.255)
All of the servers (DNS, DHCP) and the Gateway router are in the same device (The modem/router the ISP gave you) and this device has an IPv4 address of 192.168.2.1
 
Because of this we are going to configure the following sub net for the new modem/router.
IPv4 addresses - 192.168.1.x (192.168.1.1 - 192.168.1.255)
All of the servers (DNS, DHCP) and the Gateway router are in the same device (The new modem/router) and this device has an "WAN" IPv4 address of 192.168.2.254 on sub net A and an IPv4 address of 192.168.1.1 on sub net B (The sub net all of your computer will be on).
 
Reset your new router to factory defaults (should be a button for that). Set up the new router as outlined on page 12 of the manual (1.6.1 wired connection) make sure you connect from a standard port on the ISP router to the WAN port of your new router. Connect your computer directly to the new router with an Ethernet cable (or connect to the default Wifi network if the details are written somewhere). Navigate to the web GUI for your new router http://router.asus.com (2.1 Logging into the Web GUI). This should start the QIS wizard for connecting to the internet. This should detect that the sub net above it is trying to give it an IPv4 address (for Automatic IP (DHCP) you should be able to just click next. Then it will get you to configure your Wifi network, you can use anything that you want but give it a different name (SSID) to the Wifi network from your ISP router. If everything works perfectly the new router should be up and running make sure you change all of your devices across to the new Wifi or plug them into your new router. Any device that you leave connected to the ISP router will not be able to see the other devices as they will be on a different sub net. Things to note...
When connected to your new router you will probably not be able to manage the ISP router, you will have to connect to the ISP router Wifi of plug directly into it to change setting. If you set up any server in your home that you want access from the internet (Plex, VPN, Game servers) you will have to change your new router WAN connection Type from Automatic IP to static IP. This will let you set up the port forward from your ISP router to your new router and the you can set up a port forward from your new router to the server. (I would set a static IP of 192.168.2.254 anyway just to ensure stability - if you want advice on what to set the option to when changing this please post a screen shot showing the settings that it is asking for) To ensure stability you should remove 192.168.2.254 from the ISP modem DHCP range if you do item 2. This will ensure that no other device is given the IPv4 address that your new router is using (this should not be a problem anyway as you would have to have 250 devices connected to the ISP router before it would give a new device this address). You should try navigating to http://192.168.2.1 when connected to your new router as this could let you connect to your ISP router manager when connected to your new router (this might work depending on how your new router handles routeing and if your ISP router accepts connections from outside of its sub net). We can try and get this to work later if it is important to you an maybe even add a DNS record for it to your new router so that you can navigate to it using a name instead of an IP address. This should be enough information to get you going. If you have any issues post here or email me Timothypage.TP@gmail.com as i might not see your post. (will be away the next two days).