IPV6 Networking, best practices?

I'm setting up IPV6 in my home so I can learn more about IPV6. So far
I've got more questions than I've learned about IPV6. So far I've
spent a lot of time reading but it seems like I need to spend a lot
more time reading. Here are some of my questions:

- How do I get IPV6 addresses for my home? I doubt I'll get any as it
looks like I have to wait until the ISPs catch up. I have a Go6
tunnel but it gives me a /128 (I may need to do a lot more reading
as some imply that I might be able to get to my other device from
the V6 network).

- Is there software like a NAT gateway for IPV6 to IPV4?

- What IP address should my IPV6 apps bind to? I've been playing
around with getaddrinfo and getnameinfo they seem simple
enough. I've got djbdns working with IPV6 but one of its apps binds
it self to an address like: ::ffff:127.0.0.1:53 (IPV4 Mapped
addressing) but this is not one of the IPV6 addresses that I have on
my interface.

- Are there any best practices papers available? So far I've not found
any but there's a lot of information that I've reading through.

Sorry if the questions are stupid, I know I have a long way to go and
I'll keep reading and learning.

Thanks

--
Linux Home Automation Neil Cherry (E-Mail Removed)
http://www.linuxha.com/ Main site
http://linuxha.blogspot.com/ My HA Blog
Author of: Linux Smart Homes For Dummies

Hello,

Neil Cherry a écrit :
>
> - How do I get IPV6 addresses for my home? I doubt I'll get any as it
> looks like I have to wait until the ISPs catch up. I have a Go6
> tunnel but it gives me a /128 (I may need to do a lot more reading
> as some imply that I might be able to get to my other device from
> the V6 network).

For local IPv6 connectivity only, you can use "Unique Local IPv6 Unicast
Addresses" as described in RFC 4193. For global IPv6 connectivity, you
can use 6to4 addresses with automatic tunnelling, or another
point-to-point tunnel broker which gives at least a full /64, such as SixXS.

> - What IP address should my IPV6 apps bind to?

The one you decide according to your needs. I cannot be more precise
without further details.

> I've got djbdns working with IPV6 but one of its apps binds
> it self to an address like: ::ffff:127.0.0.1:53 (IPV4 Mapped
> addressing) but this is not one of the IPV6 addresses that I have on
> my interface.

IPv4-mapped IPv6 addresses are used for IPv4 communications on an IPv6
socket, i.e. the socket is IPv6 but the actual packets are IPv4.
::ffff:127.0.0.1 represents the IPv4 loopback address 127.0.0.1. If an
application binds only to such an address, it will allow only IPv4
communications.

On Thu, 27 Mar 2008 20:08:50 +0100, Pascal Hambourg wrote:
> Hello,
>
> Neil Cherry a écrit :
>>
>> - How do I get IPV6 addresses for my home? I doubt I'll get any as it
>> looks like I have to wait until the ISPs catch up. I have a Go6
>> tunnel but it gives me a /128 (I may need to do a lot more reading
>> as some imply that I might be able to get to my other device from
>> the V6 network).
>
> For local IPv6 connectivity only, you can use "Unique Local IPv6 Unicast
> Addresses" as described in RFC 4193. For global IPv6 connectivity, you
> can use 6to4 addresses with automatic tunnelling, or another
> point-to-point tunnel broker which gives at least a full /64, such as SixXS.

I have g06.com as my tunnel service. A few days after posting this I
reread the tunnel instructions and found I could set my end up as a
router. I'll do that later after I buld some proper iptables. I also
found the RFC and a script to help generate the addresses. Thanks.

>> - What IP address should my IPV6 apps bind to?
>
> The one you decide according to your needs. I cannot be more precise
> without further details.

I was afraid of that. I'll need more experience to figure out what to
use and what not to.

>> I've got djbdns working with IPV6 but one of its apps binds
>> it self to an address like: ::ffff:127.0.0.1:53 (IPV4 Mapped
>> addressing) but this is not one of the IPV6 addresses that I have on
>> my interface.
>
> IPv4-mapped IPv6 addresses are used for IPv4 communications on an IPv6
> socket, i.e. the socket is IPv6 but the actual packets are IPv4.
>::ffff:127.0.0.1 represents the IPv4 loopback address 127.0.0.1. If an
> application binds only to such an address, it will allow only IPv4
> communications.

Thanks I hadn't figured that one out yet.

--
Linux Home Automation Neil Cherry (E-Mail Removed)
http://www.linuxha.com/ Main site
http://linuxha.blogspot.com/ My HA Blog
Author of: Linux Smart Homes For Dummies

Neil Cherry a écrit :
> On Thu, 27 Mar 2008 20:08:50 +0100, Pascal Hambourg wrote:
>>
>>For global IPv6 connectivity, you
>>can use 6to4 addresses with automatic tunnelling

One note : for 6to4 it is much more convenient if your router has a
fixed public IPv4 address, as the 6to4 global IPv6 prefix is based on
the public IPv4 address.

>>>- What IP address should my IPV6 apps bind to?
>>
>>The one you decide according to your needs. I cannot be more precise
>>without further details.
>
> I was afraid of that. I'll need more experience to figure out what to
> use and what not to.

Usually you want to bind to :: (any IPv6 address and, by default, any
IPv4 address) or to an IPv6 address with global scope (global address,
unique local address) that is reachable from your clients or servers. If
a socket is for local host communications only, use ::1.