Router losing connection to Cable Modem

kenne04 said:
f the problem is with Cox's implementation of IPv6, switching servers could solve the issue.

How so? How does DNS play a role in IPv6? Performance maybe, but you don't even need DNS to get a IPv6 address. 

kenne04 said:
The DNS settings in your router basically tell the router which servers to connect you to.

The DNS settings tell the router which DNS servers to connect to. It has nothing to do with DHCPv6 or getting a IP at all. Heck you can get online without DNS, if you know the IP of the website. DNS is like 411 for the internet, allowing your computer to look up the IP(phone number) of the website (address). 

I mean if this worked for you, great. Don't mean to dismiss your idea and help, just trying to make sense of it. Maybe its just Cox's DNS server is slow to respond to AAAA requests in the way the Airport router is passing them. Using 3rd party DNS is usually a good idea in general, being faster and more secure. If you want to check for yourself, check out Google Namebench. Also, I would suggest making your IPv4 stack DNS also be Googles, or you might get some conflict. 

@TonyT

Once you go into the Airport Internet connection settings and set IPv6 to link-local only your connection should be good.

The issue is actually with the AirPort, but disabling IPv6 does help the issue.  When the internet is "not working", the actual problem is the AirPort isn't responding to DNS queries.  You can still ping, ssh, telnet, or otherwise access traffic through the AirPort without issue.  DNS queries (UDP) to external services also work without issue.

The AirPort DHCP server only hands out it's self-IP-address to clients for DNS queries, rather than passing the ISP DNS settings on through to the clients.  Because of this, the AirPort becomes a single point of failure if it's internal DNS resolver fails to respond to queries.  The internal DNS resolver seems to have an issue with DNS resolution on Cox's network.  If you disable IPv6 on the AirPort, it will work for a while, but that doesn't solve the issue of the DNS resolver failing to work.  Changing DNS settings on the client (override DNS in Network Preferences) will also get you back up and running, though it's a manual setting that shouldn't be needed.

I think Apple should update the AirPort firmware to allow the passthrough of the ISP DNS settings to DHCP clients.  There's no need for the AirPort to be in the middle of that conversation anyway, and the ISP can and does provide redundant DNS servers in the event one is down.

somethingmoreunique said:
AirPort becomes a single point of failure if it's internal DNS resolver fails to respond to queries

This is the best explanation of the Apple IPv6 issue I have ever heard. Props!  I also heard a work around of using the apple utility to find out Cox's IPv6 DNS servers then manually enter them as static DNS for the IPv6 settings like seen here. Others just use Google's IPv6 DNS server 2001:4860:4860:0:0:0:0:8888 and 8844 which gets rid of the redirect traffic and Cox's slow AAAA responses. 

somethingmoreunique said:
I think Apple should update the AirPort firmware

I agree. This isn't Apple doing something to protect the customer, this is sloppy design IMO. Automatic DNS relay should only apply to IPv4 traffic until Apple can make it user friendly.

Hard coding IPv4 DNS entries worked for me as well but all I did was hard code the Cox IPv4 DNS addresses instead of allowing the Airport DNS to auto set them.  My only remaining issue is an edge case I'm still working on where Cisco AnyConnect resets my connection every 20 min on the clock.  I have not hard coded the IPv6 DNS addresses so perhaps I'll try that as well.

I'm just reposting this becuz of the long term success I've had since adjusting my Apple Time Capsule's settings to link local. It's pathetic Apple hasn't patched this yet. Hope this helps customers who are new to the tread: 

had an Apple Time Capsule(2013 tall version) w/ a Moto SB6121 w/ no problems for 2yrs. Bout 3mos ago, out of nowhere, I suddenly kept losing my connection twice a day. Soon as I rebooted the modem or the router everything was fine, but it would always return. Went to the Apple forums and learned that Apple and Moto Surfboards don't play nice w/ each other(there's an entire thread devoted to it). I'd had no problems w/them 2gether for 2yrs previously though soooo??? Problem persisted, switched to my old Cisco DPC3000(DOCSIS 3.0).  Problem still persisted, so it's not that Apple/Surfboards don't like each other, becuz it's doing it w/ the other modem too. This is the solution that has worked for me without a drop/issue for a month straight: ***I changed IPv6 settings(in the network settings and Airport utility) to link-local***. I tested it w/ my old Cisco DPC 3000, my Arris/Moto Surfboard 6121, and now my new Netgear CM-500(had to upgrade to it to reach the new Cox 300mbps speeds). NO DROPS W/ ANY OF THOSE MODEMS ANYMORE-haven't had an issue since. YOU MUST SWITCH TO LINK-LOCAL IN BOTH THE NETWORK ***AND*** THE AIRPORT UTILITY. Just changing one won't work.

1. System Preferences/network/advanced(lower right)/TCP-IP/configure IPv6:link-local only

2. Finder/applications/utilities/Airport Utility.app/click on the Airport icon/edit/internet/internet options(below)/configure IPv6: link-local only/save

Hi Kurt2112,

Thank you for your post! Please let us know if you experience disconnects with the new Netgear Gateway. My team can take a look at what's happening!

It's not just the Apple routers. My Linksys WRT1900ac started this a few weeks ago, and some at work using Netgear N600 and NightHawk models are all reporting the same issue. I've monitored my neighborhood and see everyone with squarewave signals when the downtime happens.......except me after changing one item. I have disabled IPv6, deciding not to address thru DNS changes until COX resolves the issue. Since the change, I've logged only 1 downtime this week, vs 3-4 times a day, and that's not counting 9 hours a day I have my system down to standby since I'm not home.. If it were the routers compatibility or settings in support of IPv6 and DNS config, then why so many "modern and updated with latest driver" routers seeing issues? I for one just don't want to waste time on it, and am NOT willing to beta-test a system upgrade in process. I can live with IPv4 until the issue is addressed. Cox, how about regular status updates on the issues with IPv6 and estimates on correction/completed implementations? This is wasting a lot of hours that thankfully are mostly not billable.

Apple just came out with a new 7.7.7 firmware this month. They apparently haven't updated from 7.7.3 since 2013.

Does the new TimeCapsule firmware fix the problem?  Anyone know if the update even addresses the issues?

ElDiablo said:
Anyone know if the update even addresses the issues?

Issue was addressed, but haven't heard any feed back yet if it fixes the issue. From DSLR Cox employee:

"none of those notes mention the specific fixes that went in related to IPv6 and DNS but they are in there. We've confirmed this with Apple."

@Tecknowhelp

Thanks for the link. If there were truly fixes for IPv6 and DNS in the firmware releases, they might be working for me (Chandler, AZ).

I posted in another post about the firmware releases and that it didn't seem to help. I went back to using IPv6 yesterday and have had a stable connection for 24 hours and counting. I'm not sure why the previous test didn't work, but it appears to be working now. Time will tell.

Somehow my previous attempt at a post had a glitch, hopefully it won't show up as a duplicate (incomplete) to this post.

Same Problem with dropped internet connections after I had reconfigured my Airport extreme base station router (latest version of AP Extreme with latest firmware 7.7.7) IPv6 to Automatic. Call to Cox tech help and we went through the modem/signals check and reset Modem (SB6120)  and router reset/resyart routine.  Problem remained.  No mention of IPv6 issue (don't think the tech was made aware of this). 

Next I replaced the  MotoSB6120 modem with an Arris-Moto SB6190 modem    Went through the same rmodoem check, modem and router reset routine with Cox tech. Problem with dropped connections remained.

Next switched my AP Extreme base station with an older AP Extreme (in service in 2012); dropped internet connections remained.

Next I replaced the AP Exterme base station router  with a new wired.non-wireless LinkSys LRT224 business router. The dropping internet connection problem remained.  So- it ain't just Apple routers that are having trouble with Cox ISP .

On the Apple Support Communities I found discussion that there is a problem with Cox IPv6 ongoing implementation and apple routers and the recommendation was to configure the apple routers IPv6 to Link-Local Only.

FINALLY I contacted Cox tech again today, 1 Jun 2016, to verify the IPv6 issue.  The tech I talked to said Apple had kindly notified them of the Apple router-IPv6 glitch and confirmed tthe recommendation to reconfigure IOv6 to link-Local Only.

When I mentioned same problem with LinkSys router, the tech (local Hampton VA tech people) was surprised and said they had not received any other calls from customers who had other than Apple routers. Tech said Cox will notify customers when IPv6 is fully implemented.

BOTTOM LINE: Hopefully the reconfiguring routers IPv6 will work until Cox gets IPv6 fully implemented.  HOWEVER, I believe it is VERY POOR SERVICE for COX not to have notified all their techs and their internet customers about the IPv6 issue with Apple (and LinkSys routers.  Very poor service indeed.

IPv6 is fully implemented. What did the router logs say? Modem logs? How do you have them configured? I have been running IPv6 for over a month with no problems.

I think what jpadc06 is conveying with the term "IPv6 fully implemented" is that fully implemented will be "fully" once IPv4 is no longer supported by Cox.

IPv6 itself is fully implemented, but it is still running side-by-side with IPv4, which is why those of us who had to switch IPv6 off can still connect to the Internet via Cox.

As long as Cox continues to support IPv4, we will all be fine. But there will be a day when Cox stops supporting IPv4, and only uses IPv6. When this happens, those of us who turned off IPv6 will lose our Internet connections via our Airport and other affected Routers.

The bad news from jpadc06's report above is that Apple did not fix this issue with their new just-released router firmware.

Cox cannot turn off IPv4 until they know for sure that IPv6 will work with Apple and other affected Routers natively. And then they better send out clear messages when IPv4 is going to be shut off or else Cox is gonna be flooded with calls from all of us who turned off IPv6 so we could stop the constant disconnections from happening.