DHCP advice needed for 4G modem to own router

[DanielCoffey]

I am a bit out of my depth setting up my 4G modem to integrate with my wireless router and would really appreciate some advice.

The equipment I am replacing is the usual FTTC modem in bridge mode through to my ASUS AC86U which then goes on to my (non-PoE) 16-port switch.

I now want to use an external antenna, external 4G modem (Category-6 modem, 2.4GHz wifi and own DHCP) running OpenWRT using a PoE injector and of course my ASUS AC86U to the switch.

The issue is that I don't understand the DHCP settings that I needed for these devices.

At the moment the 4G modem is set up as 192.168.1.1 / 255.255.255.0, static address. DHCP is enabled and issues address in the range 100 to 150. IPv6 is currently not enabled.

Because it has been connected to the FTTC modem, the ASUS AC86U is currently set to PPPoE with DHCP running and has a static address of 192.168.1.254. Its own pool is 2 to 253 and there is one static address assigned to a NAS box of 192.168.1.202. All other devices are dynamic addresses (wired desktop PC, Mac Mini, AppleTV, MVHR network card. Wireless iPhone, iPad, HomePod).

Which device should be running the DHCP server? What address pools should I be allocating?

The final piece of the puzzle is that for a while I may want to use my old BT FTTC connection in dual-WAN so assume it needs an address different from its current 192.168.1.1, yes?

 

[sfx2000]

I am a bit out of my depth setting up my 4G modem to integrate with my wireless router and would really appreciate some advice.

What is the 4G Modem - Vendor and Model Number...

 

[DanielCoffey]

The 4G modem is sold by OutdoorRouter and is described as a Category-6 MIMO 4G router with 2.4GHz wifi built in. Their model number is EZR30-Y6U. It runs OpenWRT.

I can't find a setting for Bridge Mode in it but I can certainly disable wireless and DHCP on the modem/router thus allowing the ASUS AC86U to handle that providing I know the settings to enter on the ASUS router's WLAN page.

 

[ColinTaylor]

If the EZR30 can't be put into bridge mode then there's little point in disabling its DHCP server. You'd typically just put the Asus into AP mode, creating another wireless access point. Of course you'd loose some of the functionality of the Asus because that would now be handled by the EZR30.

Alternatively you could leave the the Asus in router mode, creating its own separate network behind the EZR30.

 

[DanielCoffey]

Cheers. I may actually ask the manufacturers as they are very approachable. Perhaps we can get Bridge Mode added.

 

[sfx2000]

The 4G modem is sold by OutdoorRouter and is described as a Category-6 MIMO 4G router with 2.4GHz wifi built in. Their model number is EZR30-Y6U. It runs OpenWRT.

I can't find a setting for Bridge Mode in it but I can certainly disable wireless and DHCP on the modem/router thus allowing the ASUS AC86U to handle that providing I know the settings to enter on the ASUS router's WLAN page.

Let the 4G OutdoorRouter box handle the firewall/NAT, and use the RT-AC68U as an AP.

OpenWRT is very capable software, and QC-Atheros is a tier one supported platform there - and there, you also have a deep selection of packages that can be installed. Pretty much anything that AsusWRT can do can be accomplished with OpenWRT.