Need help setting up my network

[icy_fox]

Hey guys, recently got a faster line so I wanted to upgrade my infrastructure a bit too. My main modem (so the modem that accepts the connection from my ISP) is an Arris TG862. It has no QoS and is mainly used as a switch and a DHCP server. The second one is an Asus RT-N12+, which acts as a wireless router + a QoS client for the devices connected to it (it is connected directly to the Arris from the Arris´s LAN port to the Asus´s WAN port). The Asus also has DHCP enabled, but hands out addresses on the second subnet. Downstairs, I have a TP-Link TL-WR940N, which acts the same as the Asus and is also connected directly to the Arris on the WAN port. The TP-Link also has DHCP enabled, but hands out addresses on the third subnet. Now here is the problem. I have read all over the internet that DHCP should only be enabled on one router. I have tried this and I have run into many problems (I did mostly try it with the Asus). First, if I switch off Asus´s DHCP, the router becomes inaccessible and I have to reset it in order to get into its settings again. I tried changing the IP of the Asus to the same subnet as the Arris before switching off DHCP and it sort of worked. I could access the Asus´s settings and all connections went through just fine, but in the settings, it said that the internet cable isn´t connected (which it was and the connections went through fine) and the QoS applied on the Asus just didn´t work. It recommended I should switch to AP mode, but that doesn´t support QoS so it isn´t an option. What do you guys think I should do? Is having three DHCP servers on three different subnets really that bad?

Thanks for any advice

 

[BuddhaSkoota]

Hey guys, recently got a faster line so I wanted to upgrade my infrastructure a bit too. My main modem (so the modem that accepts the connection from my ISP) is an Arris TG862. It has no QoS and is mainly used as a switch and a DHCP server. The second one is an Asus RT-N12+, which acts as a wireless router + a QoS client for the devices connected to it (it is connected directly to the Arris from the Arris´s LAN port to the Asus´s WAN port). The Asus also has DHCP enabled, but hands out addresses on the second subnet. Downstairs, I have a TP-Link TL-WR940N, which acts the same as the Asus and is also connected directly to the Arris on the WAN port. The TP-Link also has DHCP enabled, but hands out addresses on the third subnet. Now here is the problem. I have read all over the internet that DHCP should only be enabled on one router. I have tried this and I have run into many problems (I did mostly try it with the Asus). First, if I switch off Asus´s DHCP, the router becomes inaccessible and I have to reset it in order to get into its settings again. I tried changing the IP of the Asus to the same subnet as the Arris before switching off DHCP and it sort of worked. I could access the Asus´s settings and all connections went through just fine, but in the settings, it said that the internet cable isn´t connected (which it was and the connections went through fine) and the QoS applied on the Asus just didn´t work. It recommended I should switch to AP mode, but that doesn´t support QoS so it isn´t an option. What do you guys think I should do? Is having three DHCP servers on three different subnets really that bad?

If QoS is important, you are defeating its purpose by having devices connected in front of the Asus (clients connected to both the Arris and TP-Link).

Having three different subnets (when only one is needed or intended) also creates quite a few problems.
Examples:
- Unable to view network printers on a different subnet
- Can't view or share media content
- Inability to view shared network files/folders
- Port forwarding becomes unnecessarily difficult when running a server (gaming, security cams, or any sort of web service).
- VoIP or Skype services become problematic when used behind double NAT.

If you favor the Asus router's capabilities, then a good solution would be to
- Put the Arris in bridge mode (modem only mode). Only the Asus will connect to the Arris.
http://arris.force.com/consumers/articles/General_FAQs/TG862G-NA-Bridge-Mode-Setup
- Have the Asus be the sole router/gateway for your network (Arris LAN to Asus WAN)
- Configure the TP-Link to be an AP only (Asus LAN to TP-Link LAN). Giving the TP-Link a static IP address outside of the Asus DHCP range will still allow you to access it's GUI.
http://www.tomshardware.com/forum/36406-43-convert-wireless-router-wireless-access-point