Comcast Support (from NANOG Digest, Vol 84, Issue 23)

Brzozowski, John John_Brzozowski at
Fri Jan 23 17:14:11 UTC 2015


The thread below was sent to me a few times, apologies for not catching it sooner.


I sent you mail unicast with a request for some information.  I am happy to help you out.

For the larger NANOG audience, Comcast has recently launched IPv6 support for our BCI products, these are our DOCSIS based commercial offerings.  This means that if you gateway device is in fact in RG mode you will be delegated a dynamic IPv6 prefix, by default customers are delegated a /56 prefix along with a single IPv6 address that is assigned to the WAN of the gateway device.  IPv6 support applies to the following makes and models:

Cisco BWG (
Netgear CG3000D (

For customers where you bring your own cable modem or have one of the above in bridge mode we have enabled IPv6 support for you as well.  However, your router behind the modem must be running software and configured with IPv6 support.  Specifically, your router needs to be support stateful DHCPv6 for IPv6 address and prefix acquisition.  We have received a number of reports from customers that the Juniper SRX does not appear to properly support IPv6.  We are working with Juniper and also recommend that you reach out to Juniper as well.

Please keep checking for updates, we will post some additional information here in the next week or so.  In the mean time if you have questions feel free to send me mail or post them here on the NANOG list.


John Jason Brzozowski
Comcast Cable
p) 484-962-0060
e) john_brzozowski at

-----Original Message-----
From: "nanog-request at<mailto:nanog-request at>" <nanog-request at<mailto:nanog-request at>>
Reply-To: NANOG <nanog at<mailto:nanog at>>
Date: Friday, January 23, 2015 at 07:00
To: NANOG <nanog at<mailto:nanog at>>
Subject: NANOG Digest, Vol 84, Issue 23

Date: Thu, 22 Jan 2015 22:42:17 +0000
From: Janet Sullivan <janets at<mailto:janets at>>
To: "'nanog at<mailto:'nanog at>'" <nanog at<mailto:nanog at>>
Subject: Comcast Support
<CY1PR0701MB1164F3448B35404BBAE671A8DC490 at<mailto:CY1PR0701MB1164F3448B35404BBAE671A8DC490 at>>
Content-Type: text/plain; charset="us-ascii"

I hate to use NANOG for this, but support has now ended a chat with me twice without fixing anything, they just kicked me off.

I'm not getting an IPv6 address on the Comcast provided cable modem/router.  I'm not getting a PD.  My machines thus have no IPv6.  I've hard reset my router 4 times while working with Comcast, and I've been told to do things like switch to a static IPv4 address, which shows a level of clue that is scary.  And before that they were convinced it was a wireless problem even though I have a wired connection, and told them that multiple times.  I've wasted two hours with Comcast today, and even when I asked for escalation I got nothing.  Just hung up on.  It's honestly the worst customer support I've ever received.  I don't think I ever got them to understand the difference between IPv4 and IPv6.

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