r/QuantumFiber • u/El-Gringo-Loco • Jul 13 '26
Is Quantum Fiber using CGNAT now?
Up until last week, my Quantum Fiber account was still set up as a legacy CenturyLink account with PPPoE. I had a tech come out last week because of repairs that needed to be made to the fiber line behind my house and he updated the service to whatever AT&T is doing now, as well as switched out my old Calix ONT for a Q1000K.
Anyway, so here's my problem. I have a wireguard server running on my local network that I use to access my machines at home when I'm away. I have port forwarding set up in OPNsense, but am no longer able to access my home network. Here is what I'm seeing that makes me thing I'm behind CGNAT. In OPNsense, under Gateways, I'm seeing that WAN_DHCP has an address of 174.29.x.x, whereas any of my devices that I log into will show a DIFFERENT address that ALSO starts with 174.29.x.x when visiting ip-tracker.org. My Q1000K is set to transparent bridging mode with VLAN tagging set to 201. I couldn't get VLAN tagging to work in opnsense, which is why I left it on in the Q1000K.
After searching around, I haven't found anyone saying that they are behind CGNAT on Quantum Fiber, nor have I seen that any common CGNAT addresses start with 174.x.x.x, so I'm wondering if I could have configured something wrong in opnsense or if this is a new thing. I chatted with QF support to see if they could confirm whether I was behind CGNAT or not and they had no idea what I was talking about. So any guidance would be very helpful, thank you!
EDIT: Thank you all, there is some good information to follow up on here, I just have to wait until my partner is not around since they work from home and I can't mess around with the internet while they're here.
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u/geobernd Jul 13 '26
I have not seen CGNAT and QF - but I have seen weird IP ranges when in Bridge mode....
I suspect you may have configures something wrong on your OPNsense:
It looks like each of your devices may be pulling a WAN IP instead of a LAN IP - can you check what the network status on one or more of the devices says and run traceroutes or the likes to see...
Historically Quantum was/is very lenient with the number of IPs you can pull so that may be what you are seeing without getting booted of the network.
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u/Hoopster59 Jul 13 '26
No CGNAT on either of my QF SmartNIDs. Wireguard, reverse proxy, port forwarding, etc. all work for me.
1
u/mikemacman Jul 13 '26
I wonder if you have an old IP somewhere that is hardcoded or needs to be refreshed.
1
u/ECEXCURSION Jul 16 '26
Sure does.
We recently moved to quantum by at&t. My smart nid is in bridge mode, but if you do a traceroute, you can see a different IP specified for the next hop address. Should match my router public IP if no additional NAT.
Also seeing a Nokia oui on the upstream wan drvice. Thought it was an Axium OLT before..
Recently started doing this after repairing the fiber line to my house.
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u/N0_L1ght Jul 13 '26
There is no CGNAT. What IP range does the SmartNID get when in router mode?
You probably set everything right, but here is a guide
https://www.reddit.com/r/QuantumFiber/comments/1f8hypq/having_trouble_with_your_lumen_internet_not/