Recommended IPv6 setting with Comcast IPv4

[neil0311]

My Comcast connection only supports IPv4 at this time, at least as indicated by the cable modem which list the "Modem IP Mode" and "DOCSIS MIMO" as "IPv4 Only."

Given that, what is the best setting for IPv6 on the RT-N66U? I was going to disable, but wasn't sure if 6to4 would be a better choice. Any suggestions, and I'll admit that IPv6 isn't something I understand well. What issues might come up as a result of disabling IPv6?

[RMerlin]

At this point, IPv6 is mostly an experimental thing (Internet-wise). Keeping it disabled will have no impact at all. You shouldn't enable an IPv6 tunnel unless you were prepared to subscribe to a tunnelling service (such as Hurricane Electric's TunnelBroker) and configure it. And in most case it will result in a drop of performance when accessing some IPv6 enabled sites such as Youtube, depending on how close network-wise you are to HE's tunnel endpoint.

[m00ster]

Originally Posted by neil0311

My Comcast connection only supports IPv4 at this time, at least as indicated by the cable modem which list the "Modem IP Mode" and "DOCSIS MIMO" as "IPv4 Only."

Given that, what is the best setting for IPv6 on the RT-N66U? I was going to disable, but wasn't sure if 6to4 would be a better choice. Any suggestions, and I'll admit that IPv6 isn't something I understand well. What issues might come up as a result of disabling IPv6?

Hello,

The setting you are describing on your modem where it says ipv4 only is only for the management interface of the modem not the customer interface. You may have full ipv6 service.

the correct setting for comcast ipv6 is the DHCP with PD option. Try setting that and saving/rebooting your router. I have comcast and ipv6 works perfoect for me with the AC66 router.

-Jon

[neil0311]

Thanks Jon. How can I test to see if IPv6 is enabled on my connection?

[m00ster]

Originally Posted by neil0311

My Comcast connection only supports IPv4 at this time, at least as indicated by the cable modem which list the "Modem IP Mode" and "DOCSIS MIMO" as "IPv4 Only."

Given that, what is the best setting for IPv6 on the RT-N66U? I was going to disable, but wasn't sure if 6to4 would be a better choice. Any suggestions, and I'll admit that IPv6 isn't something I understand well. What issues might come up as a result of disabling IPv6?

Originally Posted by neil0311

Thanks Jon. How can I test to see if IPv6 is enabled on my connection?

open a cmd prompt and type ipconfig /all and see if you see something like:

IPv6 Address. . . . . . . . . . . : 2601:c:9e:6:886:4b69:d0db:e8ff(Preferred)

you can also try:

ping www.kame.net

if you get a response back from a ipv6 address, you have ipv6.

-Jon

[neil0311]

Assuming that I need to enable DNS and router advertisement as well as setting connection type to "Native with DHCP-PD"

[KevTech]

Originally Posted by m00ster

Hello,

The setting you are describing on your modem where it says ipv4 only is only for the management interface of the modem not the customer interface. You may have full ipv6 service.

the correct setting for comcast ipv6 is the DHCP with PD option. Try setting that and saving/rebooting your router. I have comcast and ipv6 works perfoect for me with the AC66 router.

-Jon

Wait a second...not all Comcast customers have access to native IPv6 yet.

All of the Arris DOCSIS 3.0 C4 CMTS now have IPv6 but many Cisco CMTS still do not.

It all depends on what CMTS serves your area.

I am in a Cisco area so I have router set to 6to4.

Here is a map of IPv6 enabled areas for Comcast:http://goo.gl/maps/sL3Z

If you are not in one of these areas then you most likely do not yet have native IPv6 available to you through Comcast.

[neil0311]

Originally Posted by KevTech

Wait a second...not all Comcast customers have access to native IPv6 yet.

All of the Arris DOCSIS 3.0 C4 CMTS now have IPv6 but many Cisco CMTS still do not.

It all depends on what CMTS serves your area.

I am in a Cisco area so I have router set to 6to4.

I'm outside Atlanta, so I'm assuming my Comcast connection doesn't have IPv6 enabled. If it's not, which I think is the case, then do you recommend setting the router to 6to4 or to disabled? If 6to4, any changes to the defaults needed? Leave router advertisements on and the Anycast relay IP to 192.88.99.1?

I did ping www.kame.net and only get a reply from an IPv4 address.

[KevTech]

See my previous post as I added a map.

[m00ster]

Originally Posted by KevTech

See my previous post as I added a map.

Hello,

It is possible you don't have ipv6 service if you are using Cisco equipment in your plant. The worse thing that will happen is you do not get a ipv6 address or connectivity, pretty much the same thing you had before you enabled ipv6 support. You can get a tunnel from a broker if you really want it regardless.

-Jon