Question about AP mode vs Router mode

[LeapFrogMasterRace]

So I get my internet through coax, I have an ISP Router/Modem combo and I disabled the router functionalities (which were garbage obviously) and use my AC1900 Nighwhawk (R6900) for my wifi. The problem is that I am in AP mode and I want to use QOS which can only be done in router mode (the ISP ARIS modem has no QOS settings itself). From what I understand about networking AP mode is normally used for offices that have a server with Ethernet  outlets in the walls or something?. 

 

1. I am wondering if I can switch over to Router mode on my Nighwhawk without any issues? 
2. What are the Pros and Cons of AP vs Router mode?

I hope I didn't enable AP mode in the past for some good reason and forgot .

[Electronics Wizardy]

So if you moden is just working as a modem, use the ac1900 as a normal router. 

 

Router mode is if you want it to do nat, can you turn off nat on the isp router/modem?

[LeapFrogMasterRace]

6 minutes ago, Electronics Wizardy said:

So if you moden is just working as a modem, use the ac1900 as a normal router. 

 

Router mode is if you want it to do nat, can you turn off nat on the isp router/modem?

The options are 

RoutedWithNAT
RoutedWithoutNAT
Bridged

 

Does NAT need to be off for Router mode?

[RobbinM]

Regular mode would be with NAT.

If you use something else as your Router/firewall, set it to bridged.

[LeapFrogMasterRace]

 

3 minutes ago, RobbinM said:

If you use something else as your Router/firewall, set it to bridged.

Wait so all the wifi devices have the same IP because the modem is set to NAT currently?

 

Is this what you are saying:

1) Bridged on ISP 

2) Bridged on AC1900 

4) NAT management is now up to the Wireless Router

3) QOS is now manageable by AC1900.

 

Can I still use NAT for security after doing this?

[RobbinM]

Almost, you're off on point 2.

 

With ISP box bridged, you basically end up with a modem.

You then connect your AC1900 'router' to your ISP 'modem' and it should work perfectly, including NAT on your AC1900 'router'.

[LeapFrogMasterRace]

1 minute ago, RobbinM said:

Almost, you're off on point 2.

 

With ISP box bridged, you basically end up with a modem.

You then connect your AC1900 'router' to your ISP 'modem' and it should work perfectly, including NAT on your AC1900 'router'.

Ah I see, lets say I didn't set the ISP box to bridged and set the AC1900 to router what would happen just out of curiosity? Thanks for the help this stuff had me really confused. 

[RobbinM]

That should work, and your devices should get internet service like you used to BUT: both routers should be on different IP pools, e.g. your ISP box would hand out 192.168.1.xxx adresses and your own router in the 192.168.2.xxx range. If you let them handle the same range, the built in DHCP servers in the routers will have a battle and bring down the whole network with it.

 

For devices that go through both boxes, they will be extra secure. If somebody got through your ISP box firewall then they'd still have to go through your other routers firewall to get to the device.

 

That also makes it a more difficult process to forward a port of a device that handles its connection through both boxes because the adress has to be translated twice, and thus both routers will need to have a portforwarding rule installed for that single forwarded device.

 

In general, it is good practice to only have 1 router in your network for troubleshooting purposes. If you need to extend the Wi-Fi range of your network, there are better ways to do that than to cascade a couple of routers.

[LeapFrogMasterRace]

@robbinm

So everything is working but I can't access my ISP box admin page anymore I can still access the AC1900s though.

 

Update: To access the modem in bridge mode I need to reset it using the button but it's fine for now.