Arris T25 Can't Get an IP from DHCP

https://www.reddit.com/r/PFSENSE/comments/rhi734/dead_beef_everything_is_working_fine_but_the/ 

Not much to go on here. Got more details ? Do you have an active Comcast connection ? Has the modem been activated for service ? Have you tried power-cycling / rebooting it ? Is it a new installation / modem ? Did it ever work ? Is there also a separate router in the mix here ?

I'm posting this from my cellphone.

It all started around 10pm last light. I got the your ISP's DHCP server does not function properly error on my RT-AC68P router. 

So, I decided to plug my modem directly into my PC. When I go to the Arris T25 page on my PC. It doesn't show any attempt to obtain an IP under CM state.

Also only the first three lights are solid. The MTA fails and the phone icon doesn't light up.

Edit: I forgot to mention that Comcast can't see or connect to my modem now.

I don't have an internet connection on my PC. So I have to send screenshots to my phone.

The "dead beef" IPv6 router thing is normal for devices plugged into the modem.  Your router could also use them.   Modems send the router advertisements for IPv6.  DHCPv6 does not tell you what your router is.  My NetGear modem gives me 8 of them.  They all start with fe80::dead:beef: followed by two more groups.  fe80::dead:beef:1:1 for example.  fe80 means it's a link local address.  Link local addresses are only valid on the same subnet and are not routeable.  Why dead beef?  No idea.  I'd have gone with fe80::300:fd3a (mo OFDMA, mo being short for more) myself.  It is useful to have a distinctive link local address though.  It makes them easy to spot and lets support ask "do you see a bunch of addresses starting with fe80::dead:beef?"

Have you called Comcast or at least checked for outages?  This looks like an issue upstream from the CMTS to me.  Your modem is still connected, signal stats look ok to me (maybe EG can spot something), but nothing works.  I've had that happen.  Back when I had TV service there were a few instances where the phone and Internet went down but TV still worked.  It was a problem on Comcast's end.  I couldn't be sure at the time, but it was obvious after they fixed it.

I think it's a modem issue. I'm back on my pc using an old Arris SB6141 modem that I had lying around. I called Arris they're going to replace my T25. They sent me a FedEx label to send my T25 to them and then, they'll ship me a new T25.

That could do it.  I should have mentioned that as a possibility really.  Glad you're back online and I hope the replacement fixes the problem.

@SuperGotenks 

The signal status values were all good / within specs at that snapshot in time. Are there any modem RF error log entries being shown ? If so, please post them as well in their entirety (copy and paste them, don't post a screenshot) but redact the CM MAC and the CMTS MAC addresses for your privacy. They are considered to be personal information. The posting of personally identifying information is a violation of their forum guidelines. The forum bot will not allow your post to be seen publically.

I took the modem to FedEx this morning to be shipped off. Now I just have to wait for the replacement.

I finally got my replacement modem from Arris today, 7/5. There's quite a few changes that I'ved noticed even though they have the same model number. The original T25 that I ordered from bestbuy.com had a red box inside of the white overlay. It advertised up to 10 Gbps. It had an Intel logo on the modem and advertised intel on the box.

The new one that they sent me only advertises up to 2 Gbps. It's one solid box with blue accents instead of 2 pieces like the old one. The AC adapter is by a different company called Netbit. There's no mention of Intel anywhere. Does anyone know if there are different versions of the T25 or something? Different chipsets maybe?

Does the new one work?

It could be a different chipset or they might have just removed the branding.  Intel's gotten a lot of bad press for bugs.  They may well have fixed them by now, but there are a lot of people running around saying avoid Intel based modems so I could see why Arris would take the Intel logo off the box and product.

The old one was as 10Gbps as the new one is.  ~10Gbps is the maximum DOCSIS 3.1 can handle, but the T25 only has 2 1Gb ethernet ports, so the most you can get out of it is 2Gbps.  I assume it supports bonded interfaces if you use a router with support for it.