IPV6
Internet Protocol version 6
Back to Top

Publically Routable IPv6 Addresses?

Highlighted
hphinc
New Member

Publically Routable IPv6 Addresses?

I see have have a /64 IPv6 address space. How do I go about making some of these IP addresses publically routable? I have 18 IPv4 IPs, and I need to add IPv6 addresses to each of those IPs to make my AAAA records resolve to those boxes.

Trusted Forum Contributor

Re: Publically Routable IPv6 Addresses?

BY "/64 address space", do you mean that you are seeing global-scope 2601::/64 addresses on your equipment? Or just link-local (fe80:Smiley Happy  addresses? If you mean the first, then they should already be publically routable.... If you have your own domain, you can just add a new AAAA record and point it to this Comcast-provided 2601:: address. I have done this exact thing with my own domain, primarily used for hosting my email server.

 

At the moment, all Comcast gateways will hand out DHCP dynamic v6 address spaces to all connected equipment, and the Netgear CG3000DCR will also allow sub-delegation to your own connected routers. Static IPv6 addresses are not supported at this time.

Forum Contributor

Re: Publically Routable IPv6 Addresses?

It does not work in all cases, call into Comcast and open a support ticket.  I can ipv6-ping out just fine and get replies but ipv6 pings from remote hosts to my host fail.

Trusted Forum Contributor

Re: Publically Routable IPv6 Addresses?


@tmittelstaedt wrote:

 I can ipv6-ping out just fine and get replies but ipv6 pings from remote hosts to my host fail.


Are your hosts configured to accept unsolicited ICMPv6 echo-requests? And are your routers, if any, configured to forward these requests?

Forum Contributor

Re: Publically Routable IPv6 Addresses?

There are no routers in between my hosts and the SMC.  As you well know Comcast does not allow for customers

to run their own routers.  Any static IPv4 subnets must consume an IP on the LAN interface of the Comcast router.

 

IPv6 pings in between hosts work fine.  This is a Unix network not a toy network. ;-)   FreeBSD by default is open unless you turn on ipfw.

Trusted Forum Contributor

Re: Publically Routable IPv6 Addresses?

I run several Linux networks; I am aware of their quality.

 

Do packet traces during ICMP6 pings show anything useful?

Forum Contributor

Re: Publically Routable IPv6 Addresses?

The issue is the SMC modem's internal IPv6 firewall it is very broken.  There is a hack I finally worked out in conjunction with just experimenting with a helpful Comcast support person that allows for it to work with a single host that I am detailing in another post.  I would shift to a Netgear except that there are reports of these failing under higher bandwidth loads.