[VoiceOps] Cox cable "outages" and a solution

Jared Geiger jared at compuwizz.net
Sat Mar 19 15:42:44 EDT 2016

When Cox first launched IPv6 in my area, I'd lose v6 routing randomly every
few days until I manually renewed the address on my router. Then I found
out one tiny config difference between Cox and Comcast is that Cox doesn't
support rapid commit renews. So I removed that from my router config and I
haven't lost routing since.

Also if your customers use a Motorola/Arris SB6183 model modem, the
firmware Cox uses has a major bug where it drops packets. Cox is testing
new firmware and rolling it out to those who request it. See:


On Sat, Mar 19, 2016 at 10:10 AM, Fred Posner <fred at palner.com> wrote:

> I had a major issue with Cox when they were deploying ipv6. They set a
> rate limiter on packets, and any voip call would trigger it. Once the
> call ended, the speed would come back.
> The way we proved it was to ping from the router to the immediate hop
> after the modem... once we could prove it this way to the field tech,
> they got "tier 3" to call a network engineer and resolve it.
> Hopefully it's similar.
> Fred Posner
> The Palner Group, Inc.
> http://www.palner.com (web)
> +1-224-334-FRED (3733) direct
> On 03/19/2016 12:48 PM, Carlos Alvarez wrote:
> > I'm posting this info here because I know quite a few of us have BYOI
> > customers and may be affected by this.  Cox users have been reporting a
> > lot of outages lately in certain areas (it seems to cluster by whatever
> > areas Cox is making changes in).  I found that when there is a supposed
> > outage, the only thing that fails is DNS. You can still
> > ping/trace/connect with an IP address. I looked at the router's
> > DHCP-assigned info and found that it was seeing an IPv6 DNS as its
> > primary, with the usual two IPv4 servers as secondary/tertiary. Oddly,
> > this didn't seem to happen right away, but would happen after the router
> > had been up for a few hours. My best guess at the root problem is that
> > Cox isn't properly handling IPv6 yet, even though they are advertising
> > it to the router.  Completely disabling IPv6 in the router fixes it.
> >
> >
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