Right now, I have a home network setup behind a Netgear router. That router has a public IP address I get from Comcast. I also have a computer setup on my home network running Linux that runs a DHCP Server and a DNS server. The DHCP server automatically hands out internal IP addresses in the 192.168.0.xxx block. The DHCP server tells clients to use that internal DNS server, and also registers a DNS name and search suffix so I can connect to other computers by name without typing in an IP address.

If I wanted to switch over to IPv6 (as soon as Comcast supports it), I'm wondering what all needs to change.

Obviously, I need to make sure my cable modem supports IPv6 or buy a new one. I have a fairly new Netgear router, so it probably supports IPv6 or can be made to via a firmware upgrade.

However, I believe I would no longer use IPv4 internal addresses and instead get a block of IPv6 addresses from Comcast. Obviously, I don't want to be typing in IPv6 addresses to connect to other computers on my home network. I believe this means I would still want to run a DNS server at home, and I'd want to configure these settings via DHCP which would mean running my own DHCP server as I do now.

I think the ideal setup would be to keep my current configuration, but configure my DHCP server to obtain public IPv6 addresses from my ISP rather than use a hard coded block of IPv4 addresses. Is this possible to do?


2 Answers 2


Comcast will be taking a dual stack approach, which means that both IPv4 and IPv6 will be in use. Your modem will be assigned an IPv6 subnet in addition to the current IPv4 address (using DHCPv6 AFAICT). Your Netgear router should expose that IPv6 subnets to the LAN devices using SLAAC or DHCPv6 (but still provide IPv4 via DHCP). The devices will then have both a public IPv6 address, and a private IPv4 address. When doing DNS lookups they will check for IPv6 AAAA records and try to make an IPv6 connection if there is one, but otherwise fallback to IPv4 A records and an IPv4 connection. You can use either IPv6 or IPv4 to communicate between devices in your LAN.

  • What I want to do is give each computer on my network a name, so I can do things like ping laptop instead of ping - In the past, I've used DNS for that. Does this approach still make sense with IPv6? Jun 6, 2012 at 19:03
  • @MikeChristensen Name resolution methods are (practically) the same for IPv6. Jun 6, 2012 at 19:23
  • @techie007 - Yea, I guess what I'm wondering is if I can use my own DHCP server but still use Comcast assigned IPv6 addresses. I'm guessing I can. Jun 6, 2012 at 19:37
  • 1
    @MikeChristensen Yes, you can internally setup DNS which resolves to IPv6 addresses (using AAAA records), and you can setup DHCPv6 to hand out IPv6 addresses (or use SLAAC to allow devices to configure addresses themselves).
    – mgorven
    Jun 6, 2012 at 20:02
  • Thanks! Sounds like everything I want to do would be possible with the right configuration. Jun 6, 2012 at 20:04

The reserved private address blocks in IPv4 remain the same in IPv6, so nothing would really need to change in a private network. You shouldn't need to do anything, since your router already supports IPv6. As far as network configuration is concerned, you usually only want your Internet gateway (in your case, your Netgear router) to have a public address. That makes it more difficult for an outside hacker to access your private network.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.