Trouble getting set up with a cable modem

[BathToast]

Hey all,

Bit new to things here. For the longest time i've just used whatever netgear i felt like grabbing off the shelf. However, lately i've run into a bit of an issue. Recently i've set up my home lab to tinker and explore the prospect of expanding my career field into networking and have a way to dink with that stuff at home. I figured a good thing to do would have myself my own router running on its rackmounted hardware. So far it seems like a general reccomendation I've gotten is OPNsense.

Well, I'm pretty much pulling my hair out.

So my situation is as follows:

I got it installed on my little Dell 210 II, clean and simple and I'm pretty much able to access it fine. However. It spat back an IP from my modem of 0.0.0.0/8 on the WAN connection

I've tried configuring just about whatever i can think of between these two. The Modem is in bridge mode, so it should be handing things over to the OPNSense Box just fine, but if i let it try and autoconfigure itself with a factory reset it pulls an ip of 192.168.1.103/24

This doesnt even make much sense to me because if it was the OPNSense box doing this, i have it set to hand out addresses from .50 to .200, and if it was the modem giving it this then it would be starting from .2

There were a few times, back when the Modem was running as a router I could ping the outside world, and the only reason I can post on the forum is because im hooked directly to the modem itself, and it has an internet connection just fine, and my Nighthawk router works just fine if i plug it in. But for whatever reason, either im crazy/stupid/etc but this stupid thing will not link up to the internet no matter how hard i force it.

I'm at my wits end and have tried everything I can think of. I'm working with the device through direct connection to the hardware (good ol' keyboard and mouse with black and white text) rather than the Web GUI. Is there anything I should check, do, start over, etc to try and get this thing on track. Or am I crazy and using the wrong OS entirely and should be on OpenWRT or something?

Its worth noting i do not need wireless from the router itself, I have a Cisco switch i will be using to connect everything up with, and for wireless I plan on getting a Ubiquti arrangement up and running. However, i cant even get my laptop to get internet from this so far.

Anything will help

Scratch that, its up and running.

So turns out the case was, after getting so irritated at the issue I had to get up and walk away from it, that it seems my ISP has an indeterminate amount of time (Presumably about 30 minutes) where when new hardware changes occur that you need to let it sit and get comfy before it will latch onto anything. Discovered this after doing a bit of digging and coming back from having something to drink and cool my nerves. If you run into this issue like i did:

1) Ideally start from factory resetted equipment.

2) Connect the OPNSense box to the Modem, run the setup. It should have an IP assigned to it on the same subnet as the modem

3) Switch to bridge mode on the modem and let it do its thing

4) Go make yourself some tea/hot chocholate/screwdriver/etc whichever you prefer and wait a hot minute

5) Come back and reboot your OPNSense box and you should be all set and have your public IP now.

6) Dont constantly get irritated at the hardware and reset and try again, because doing this prevents it from snatching the IP from the DHCP.

For anyone additionally curious to details:

I'm using WOW Cable, 200mbps service, through an Arris TG2472G Modem, Running into a Dell R210 II with    OPNsense 22.1.2_2-amd64 baking on it.

For the time being i have it spitting out the LAN signal into my old Nighthawk router in AP mode until i can get our Ubiquiti WAP's setup, its 6am, im tired.

Cheers lads.

[Demusman]

Any time you change the MAC address directly conected to a cable modem, just reboot the modem.
It 'learns' the directly connected MAC, you can see this if you log into the modem.
Rebooting it will clear that so it can learn the new one.
Or wait until DHCP lease expires like you did.

[lilsense]

This is not always the cae with some ISP's. After changing MAC, I'd highly recommend turning off the ISP modem/bridge and wait at least 5 - 10 min. This will clear the ARP table of the MAC sticky in ISP switch. It should be fine after that. I have noticed this may take as much as 30 minutes, so your mileage may vary (YMMV).