Turn off "DHCP Server" means just modem mode?

[shoutingsteve]

I got a new ISP and I don't love it.  For one thing my media monkey server doesn't work anymore.  So I logged into the att modew/router combo unit and changed the DHCP Server from "on" to "off" via the drop down menu.  My Deco brand mesh is attached to all this, which acted as my router when I had trashy straight forward internet with just a modem from the cable company.  Currently I have changed it to:

fiber line at the wall  --> att box (modem and router with DHCP off) --> Deco mesh unit --> unmanaged switch (port 3) --> Desktop computer (port 1), FreeNAS server (Port 2).

The att router had DHCP time set to 24 hours, so after 24 hours should I expect it all to hit the fan or is my Deco now going to take over and assign addresses like it used to?  (and might this have been the reason that the media monkey server didn't work)

[Alex Atkin UK]

31 minutes ago, shoutingsteve said:

I got a new ISP and I don't love it.  For one thing my media monkey server doesn't work anymore.  So I logged into the att modew/router combo unit and changed the DHCP Server from "on" to "off" via the drop down menu.  My Deco brand mesh is attached to all this, which acted as my router when I had trashy straight forward internet with just a modem from the cable company.  Currently I have changed it to:

fiber line at the wall  --> att box (modem and router with DHCP off) --> Deco mesh unit --> unmanaged switch (port 3) --> Desktop computer (port 1), FreeNAS server (Port 2).

The att router had DHCP time set to 24 hours, so after 24 hours should I expect it all to hit the fan or is my Deco now going to take over and assign addresses like it used to?  (and might this have been the reason that the media monkey server didn't work)

You need bridge mode, all turning off DHCP Server does is stop the router giving out LAN IP addresses so yes, everything will stop working.

It even mentions on that page that Cascaded Router may be what you need with IP Passthrough turned on.

[shoutingsteve]

It's strange because I am now seeing two different IP addresses for the same piece of hardware (the deco mesh primary unit):

192.168.1.66 and 192.168.4.1.  typing either one into the address bar takes me to the configuration screen for the mesh unit.

I tried enabling the cascading router, but can't figure out what to put into the address boxes for the screen posted above. Any ideas?

[Donut417]

8 hours ago, shoutingsteve said:

reason that the media monkey server didn't work)

Well when you connect two routers together you have double NAT. That's why the server probably had issues. AT&T doesnt support bridge mode on its Gateways, you need to setup IP pass thru mode. I personally dont know how to do it, I just know it's what you need to do if you're going to use your own router. 

[Lurick]

Firewall > IP Passthrough

Allocation Mode > IP Passthrough

Passthrough Mode > DHCPS Fixed

Select your Deco router MAC from the list

Save

[Alex Atkin UK]

On 7/8/2023 at 2:29 PM, Donut417 said:

Well when you connect two routers together you have double NAT. That's why the server probably had issues. AT&T doesnt support bridge mode on its Gateways, you need to setup IP pass thru mode. I personally dont know how to do it, I just know it's what you need to do if you're going to use your own router. 

I mean technically IP pass though is still bridge mode, its just you have to configure it yourself rather than a one click solution.

[Lurick]

6 minutes ago, Alex Atkin UK said:

I mean technically IP pass though is still bridge mode, its just you have to configure it yourself rather than a one click solution.

The thing with AT&T's implementation though is it's not true bridge/pass through, it's kind of a hacky way around since you can still configure the firewall and it still filters traffic, it just kind of but not really passes the public IP through but acts like a transparent firewall still allowing blocking if setup. It's close but just a tad different than what I should really be imo.

[Alex Atkin UK]

4 hours ago, Lurick said:

The thing with AT&T's implementation though is it's not true bridge/pass through, it's kind of a hacky way around since you can still configure the firewall and it still filters traffic, it just kind of but not really passes the public IP through but acts like a transparent firewall still allowing blocking if setup. It's close but just a tad different than what I should really be imo.

I get the feeling AT&T are control freaks, considering they changed my friends LAN subnet when they enabled IPv6 - because they wanted all users to be consistent.  I guess it makes sense for troubleshooting, but ironically they later had to disable IPv6 as their v6 network performs poorly.