AX-86U and IPV6 with Xfinity???

[phillyaj]

Greetings all,

After racking my brain for the past few weeks as to WHY my speed dropped from 800-900 to 500-600. I even went out and got a new Modem (Arris S33). I found out that my AX-86U (on Merlin 388.1), had IPV6 enabled. I turned it off and it's working correctly. (Getting 1000-1200Mbps from spdMerlin at the router).

Anyone know why IPV6 is a problem on the AX-86U with Xfinity???

***I remember having this issue previously when I was using the Arris SB8200--

 

[heysoundude]

***I remember having this issue previously when I was using the Arris SB8200--

How did you fix it then? (was it a router IPV6 config oopsie/oversight?)
Are you sure you have Native IPv6 available?
comcast doesn't seem to have any quad-A records that I can find (I'm not really looking that hard though), so their support of IPv6 may be lacking...or it's not enabled on your gateway device?

Have you provisioned the cable modem?

Establish An Internet Connection - Arris SURFboard S33 User Manual [Page 15]

Arris SURFboard S33 Manual Online: Establish An Internet Connection. Although your computer or laptop may be configured to automatically access the internet, you should still perform the following cable modem connectivity test to check that your S33 and computer or laptop are connected...

www.manualslib.com

you may need to adjust settings, ie bridge mode, if possible or you could be Double NAT

 

[Paliv]

I use native IPv6 with Comcast on my AX86u. I had no issue getting speeds to 2 devices exceeding 1300 Mbps. I don’t think speed tests run on the router are reliable once you get over 800 Mbps or so. I never saw consistent result reported by the router. But watching traffic with a speed test running on two different devices at once easily hit my max speeds consistently. Do you have AiProtection or any AQoS turned on?

 

[Wisiwyg]

At one point I had 1200 Mbps Xfinity on my AX88U. The only way I could get better than 800 was to channel bond my Netgear Modem to my router. Even though the 2x 1GB channels were coming from the same modem I was able to see the full bandwidth. At the time, I assumed it was a bottle neck with the AX88U and the incoming WAN Gb port and associated overhead. Bonding LACP on the router WAN and Lan 4 seemed to be the solution. I don't have > 1gb Xfinity service now, so can't test this assumption. But I still bond the two 1gb ports on my Netgear CM1200 to the WAN and LAN4 on my AX88U, it's using LACP. I'm unsure how this would be affected by IPv6 b/c I don't use it.

 

[phillyaj]

I do think Comcast in area has an issue with IPV6. I recall having this issue before and there is no real need for IPV6, at this point.

As of this morning...my service has been rock solid. This is output of spdMerlin on the AX-86U.

I use native IPv6 with Comcast on my AX86u. I had no issue getting speeds to 2 devices exceeding 1300 Mbps. I don’t think speed tests run on the router are reliable once you get over 800 Mbps or so. I never saw consistent result reported by the router. But watching traffic with a speed test running on two different devices at once easily hit my max speeds consistently. Do you have AiProtection or any AQoS turned on?

 

[phillyaj]

How did you fix it then? (was it a router IPV6 config oopsie/oversight?)
Are you sure you have Native IPv6 available?
comcast doesn't seem to have any quad-A records that I can find (I'm not really looking that hard though), so their support of IPv6 may be lacking...or it's not enabled on your gateway device?

Have you provisioned the cable modem?

Establish An Internet Connection - Arris SURFboard S33 User Manual [Page 15]

Arris SURFboard S33 Manual Online: Establish An Internet Connection. Although your computer or laptop may be configured to automatically access the internet, you should still perform the following cable modem connectivity test to check that your S33 and computer or laptop are connected...

www.manualslib.com

you may need to adjust settings, ie bridge mode, if possible or you could be Double NAT

IPV6 was turned ON at the AX-86U and in 'native' configuration. I recall having a similar issue once before. I think Comcast has issues handling IPV6 and TBH, I don't see a real need for it at this point.

To answer your questions....YES...I provisioned the modem successfully.. (Xfinity lets customers do it directly via their app). and the router was/has been configured properly.

I think what happened was when I did a firmware upgrade a bit ago, it must have turned on IPV6. Just one of those 'gotchas' to look out for. I spent a few frustrating days wondering why my service was cut in half.

Well, now I have a new Modem..that will keep me good up to 2.5G service on Docsis 3.1

 

[heysoundude]

I think Comcast has issues handling IPV6

I did a bit of poking about on Hurricane Electric about Comcast/Xfinity and it appears they aren't very IPv6 proactive at this point.
For me that's a no-go, because I want to be up, running and comfortable as the world transitions further because it and the interweb isn't going away or getting less used, and there are more devices on it every day.
I'd be looking for alternatives/options as far as service provider, but I'm happy your network connection is functioning as you desire.

 

[Paliv]

I did a bit of poking about on Hurricane Electric about Comcast/Xfinity and it appears they aren't very IPv6 proactive at this point.
For me that's a no-go, because I want to be up, running and comfortable as the world transitions further because it and the interweb isn't going away or getting less used, and there are more devices on it every day.
I'd be looking for alternatives/options as far as service provider, but I'm happy your network connection is functioning as you desire.

I wonder if it depends on the area. I’ve had no IPv6 issues with Comcast for the last year and a half. It has been on by default on their leased gateway/routers for a few years now. I’d be surprised if they did that and weren’t ironing things out. They seem to run screaming from customer complaints.