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New Contributor

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15 Messages

Saturday, November 29th, 2025

ipv6 delegation from Comcast business modem stopped working

On about Nov 18, my modem stopped delegating prefixes to my pfsense router.  I spent several days trying to get the issue escalated, and it finally landed with [Edited: "Personal Information"] Michele <[Edited: Language]>. She sent a tech to urgently replace my modem, and the new modem worked (successfully delegated to my router) for about an hour UNTIL it got the same update.  The new modem caused me to get a new ipv6 prefix, requiring me to spend an entire day purging the old one from freeipa and lots of other places--and that was totally unnecessary because there was nothing wrong with the original modem.  My previous ipv6 reverse delegation was delegated to my own nameservers, and the new one doesn't work, of course.  Michele did say that I would hear from the advanced DNS team within 24-48 hours, but I didn't, of course.  I am now left with two big problems, and Michele has stopped responding to me:
1.  I'm still not getting subnet delegation from the comcast modem to my pfsense router.
2.  Reverse DNS is still delegated from my old ipv6 prefix, but is not delegated from my new one; thus I have no ipv6 reverse lookup.

This is VERY frustrating. Does Comcast not test the firmware before rolling it out?

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New Contributor

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5 Messages

4 days ago

My IPv6 changed the other day and I noticed the same thing.  Also using Pfsense.  My WAN did pick up the new address, but nothing else on the LAN (Track interface, RA and tried DHCP6).  It's not as urgent for me at the moment, thankfully

(edited)

Official Employee

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276 Messages

It looks like you have attempted to post some personal information in our public forum. We have suppressed that information to keep your personal data private. Please review our Forum Guidelines below for additional information as to the type of information we want to help you protect: https://forums.businesshelp.comcast.com/conversations/announcements/comcast-businesssupport-community-guidelines/5fe0a62cc5375f08cd9613e5

New Contributor

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15 Messages

3 days ago

Is anybody going to offer to assist with these issues?

Official Employee

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276 Messages

It looks like you have attempted to post some personal information in our public forum. We have suppressed that information to keep your personal data private. Please review our Forum Guidelines below for additional information as to the type of information we want to help you protect: https://forums.businesshelp.comcast.com/conversations/announcements/comcast-businesssupport-community-guidelines/5fe0a62cc5375f08cd9613e5

Official Employee

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276 Messages

It looks like you have attempted to post some personal information in our public forum. We have suppressed that information to keep your personal data private. Please review our Forum Guidelines below for additional information as to the type of information we want to help you protect: https://forums.businesshelp.comcast.com/conversations/announcements/comcast-businesssupport-community-guidelines/5fe0a62cc5375f08cd9613e5

Official Employee

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13 Messages

3 days ago

We apologize for this incredibly frustrating and persistent IPv6 issue @user_c7e85c. We are truly sorry for the runaround you've experienced. You were promised a follow-up from the advanced DNS team that never occurred, this is not the experience we want for our customers. 

 

If you could send our team a direct message with your full name, business name, and the service address associated with your account, I'd be more than happy to look into this for you.

 

To send a Direct Message, please click on the “Direct Message” icon in the top-right corner of the screen, next to the bell icon, click the "New message" (pencil and paper) icon, then type or select " comcast_business_community". Type your message in the text area near the bottom of the window and press Enter to send your message and initiate a live session.