Seasoned Contributor

Is the PD documented?

Part of doing IPv6 is documenting the details.

 

  1. Is the PD specified somewhere?
  2. Is it a single value or tuple?

 

Of course the second question should be documented at the answer to the first question but I ask anyway.

 

On a related note is it constant across all service areas?  I've seen some comments that suggest it might not be or that it's changed over time.

8 REPLIES 8
Spectator

Re: Is the PD documented?

Can you be clearer what you are looking for?  When you request a prefix delegation, you will get back something that looks like 2606:xxxx:xxxx::/56 or 2606:xxxx:xxxx:xxxx::/64.  Like your IPv4 address, the block you are assigned can change. Generally, you will likely get the same prefix allocated if your DUID doesn't change, but it is not guarenteed - if your IPv4 WAN IP changes, expect to also see a change in the IPv6 prefix you get assigned

Seasoned Contributor

Re: Is the PD documented?


@mtg92117 wrote:

Can you be clearer what you are looking for?


I'm looking for the specifications/document.  I.e. if check Hurricane I see that I can get a /64 and a /48.  They don't make me try a selection of prefixes to determine which ones will be honored.  They tell me in the documentation.

 

They even tell me what to do to set up the /64 in case I'm unsure:

modprobe ipv6
ip tunnel add he-ipv6 mode sit remote 209.51.161.14 local 67.244.0.0 ttl 255
ip link set he-ipv6 up
ip addr add 2001:470::2/64 dev he-ipv6
ip route add ::/0 dev he-ipv6

 

Spectator

Re: Is the PD documented?

Ok. HE is MUCH different because you are not doing DHCPv6-PD, just static SIT tunnel and static /64 and /48 delegations. Also, if you also look at the HE forums, you will notice that there are a multitude of different router configurations, MOST that are user contributed,  Also from personal experience setting up a Juniper to HE, the "recipe" they give you is not always "plug-and-play" - it took a few other tweeks to get it to work.  

 

DHCPv6-PD in general will be pretty much automatuc for most everyone that only has a single subnet behind the router. The only "magic" that comes in is when you want more than a single /64.  Then you will have more moving parts, and it becomes much more router-dependant, as you have to take the block you are assigned, and carve it out to all your LAN interfaces and advertise using RADVD or DHCPv6.  I

 

A quick Google search will show a thread on this forum showing TWC offers a /56.  Don't get wrapped up that you can't request something in between like a /60 - just grab the /56 and move on. When it comes to IPv6, you don't need to think about "conserving address space" like with IPv4.  Note that HE offers only 2 options - a single /64, or a /48, which BTW is the "smallest" block many in the IPv6 community think should be allocated to customers. 

 

That said, maybe we should start a thread with links to various how-to's on configuring DHCPv6-PD on Time Warner.  Here are ones that I found when I was working on it:

 

MikroTik:  https://major.io/2014/09/11/howto-time-warner-cable-ipv6/

 

OpenWRT:  http://forums.timewarnercable.com/t5/IPv6/dhcpv6-pd-prefix-length/m-p/83116#U83116 (my config is the last in that thread)

 

Juniper SRX: https://kb.juniper.net/InfoCenter/index?page=content&id=KB30509&actp=search  (wish they had this working when I was testing out an SRX210 last year)

 

Cisco (haven't tried this): http://www.cisco.com/c/en/us/support/docs/ip/ip-version-6-ipv6/113141-DHCPv6-00.html

 

If anyone is interested, I can contribute a working Ubiquity EdgeRouter-Lite config

 

 

 

 

Seasoned Contributor

Re: Is the PD documented?


@mtg92117 wrote:

Ok. HE is MUCH different


Yes it is because they have documentation. The rest of the circumstance (tunnel, not using DHCP6 etc.) is irrelevant to my question "Is the PD specified somewhere?".  People can have opionions and even produce the results of their requests* but only TWC can provide the specification. They have an IPv6 section in the FAQs with answers like:

 

As long as IPv4 is working, your dual-stack (IPv4 and IPv6 simultaneously) configuration will still allow you to use IPv4-enabled DNS resolvers to look up IPv6 addresses.

 

Most customer-owned devices will work with IPv6.

 

But nothing about PD.

 

*my request is like this:

 

iface eth1 {
  t1 1800
  t2 3600
  rapid-commit no
  ia
  pd {
   t1 1800
   t2 3600
   prefix ::/56
  }
}

because I tried the other obvious choices not because I read the TWC specification that I can't find.

Spectator

Re: Is the PD documented?

What router are you using?  T1 & T2 (preferred lease and valid lease times) are parameters the server should provide. You should not need to set them yourself. The only thing you really should need to configure is the request for a PD, and with the prefix-length as an option. 

 

As I said before PD is very router-specific once you get past the default /64 setting. I know consumer routers like D-link and ASUS, getting the default PD is as simple as enabling IPv6 and enable PD with two check boxes in the GUI.  But there is not always support for requesting a larger block.  

 

HE has documentation because you pretty much HAD to have documentation, especially in the early years. And what they have has been collected over 15+ years (I first dealt with them in 2002 when we were doing early testing on the original 6Bone). And much of what they have has been crunched by their many customers over those years.  I agree it would be nice for TWC to have better documetation, but at this point they don't even provide ANY documentation on how to configure your own router for IPv4. The only "TCP-IP how-to's" are connecting a single host:

http://www.timewarnercable.com/en/support/faqs/faqs-internet/internettr/how-do-i-set-up-tcpip.html

 

So basically, what they all but say is: "If you connect your own router, you're on your own"

 

 

 

Seasoned Contributor

Re: Is the PD documented?


@mtg92117 wrote:

What router are you using?  T1 & T2 (preferred lease and valid lease times) are parameters the server should provide.


You're being distracted by irrelevancies and missing the point.  While I wasn't using HE in 2002 you can't configure a tunnel without certain information.  You can't configure PD without certain information unless there's no choice.  Since TWC provides choices they should document those.  There is no comparison to IPv4 because a DHCP response for an address is complete.  Presumable if you have BC with multiple addresses they provide instructions or set it up for you.

Highlighted
Spectator

Re: Is the PD documented?

And you missed my last point: PD only comes into play if you are setting up your own LAN, and as I said, from all appearances, TWC provides ZERO documentation to assist setting up your own LAN, whether IPv4 or IPv6.

 

I understand...You just want to make a point that TWC documentation sucks.  Welcome to the world of residential broadband in the US. 

Seasoned Contributor

Re: Is the PD documented?


@mtg92117 wrote:

And you missed my last point: PD only comes into play if you are setting up your own LAN, and as I said, from all appearances, TWC provides ZERO documentation to assist setting up your own LAN, whether IPv4 or IPv6.


Residential IPv4 is not related to this unless you know that getting more than a single address is undocumented or unsupported for people that pay for that service.  A single residential IPv4 address is perfectly documented -- use DHCP, there are no choices or options you can set that change what happens in the DHCP transaction.

 

If IPv6 was expected to be subject to NAT then maybe TWC could be excused -- but what do their rented boxes do?