nanog mailing list archives

Re: AT&T UVERSE Native IPv6, a HOWTO


From: Owen DeLong <owen () delong com>
Date: Mon, 2 Dec 2013 15:54:24 -0800


On Dec 2, 2013, at 15:45 , Ricky Beam <jfbeam () gmail com> wrote:

On Mon, 02 Dec 2013 17:54:50 -0500, Owen DeLong <owen () delong com> wrote:
I don't know why you think that the PC and Laptop can't talk to each other. It actually seems to work just fine. 
They both default to the upstream router and the router has more specifics to each of the two LAN segments.

You are confusing ROUTING with the WINDOWS FIREWALL (on by default)

Wired pinging Wireless will be dropped by the OS as foreign, unsolicited traffic. (I see it often enough: A cannot 
talk to B because they're in different networks.)

Meh... The firewall will get updated and will have to become more intelligent. Given that Micr0$0ft also turns on 
automatic updates by default, I'm not too worried about the people who haven't configured their windows box. Besides, 
Windows is actually losing market share these days anyway.


Micr0$0ft doesn't have to make any assumptions at all. In the IPv6 world, they can use site-scoped multicast 
(ffx5::).

People don't even know what link-local addresses are (and they don't cross links.)  Site-local (ULA) requires 
administrative configuration; no machine, by default, will have a ULA address until manually configured (i.e. they 
see an RA.)

I didn't say ULA or Site-Local. I said Site-Scoped multicast (ffx5::) specifically. (Site Local is deprecated, ULA is 
fd00::/8).

Further, according to Homenet work going on in the IETF, like it or not, most homenet gateways will be choosing and 
advertising a ULA prefix for the home in addition to the GUA prefix assigned by the service provider.

However, coming back to what I was actually talking about, mDNS/SAP/Network Browser/Network Neighborhood/whatever you 
want to call the discovery mechanism du jour can find the hosts on the other networks within the site using site-scoped 
multicast groups (which start with ffx5::/16) and could even do some of their communication (e.g. negotiating for 
changes in the default firewall posture) via that mechanism.

Frankly, if you're paying for IPv6 space, you're not too bright. You can go get a direct assignment from an RIR so 
easily for $100/year that it just doesn't make sense to pay more than that.

If you can justify it. A home user... good luck with that (a: getting the space, and then b: getting Uverse, etc. to 
use it.) For a business, I always say get your own space, unless you like re-numbering every time you change 
providers. (we've done it 5 times in 10 years. 'tho none of them have ever supported IPv6; shame on them.) [while 
"renumbering" the network may be simple, changing the prefix(es) that have been recorded in various systems is still 
a pain.]

I'm a home user. I run my own /48 ARIN assignment here. I use tunnels to routers in colo and only use Comcast et. al to 
provide transit for the tunnels themselves.

My point is that home users by and large don't pay for any address space and there's not much to be gained from trying 
to charge them for it.

Beyond home users, there's not much point in paying any significant amount of money for it.

There's no meaningful cost in providing home users with /48s... So much so, in fact, that the cost of taking even a 
single phone call complaining about an undersized IPv6 assignment probably more than pays for assigning /48s to 1,000 
customers.

Owen



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