4 ms·
University campus typically have similar, although a bit less dynamic pattern of usage, than conference type scenarios. We actually observed on different (not j
by ay 12y ago
University campus typically have similar, although a bit less dynamic pattern of usage, than conference type scenarios. We actually observed on different (not just conference, but also campus) that wireless networks in general seem to have the same curve of connection duration distribution, though with different parameters. (If you have a large WiFi net, and would like to collaborate on re-confirming or disproving this hypothesis, please let me know).
The privacy addresses refresh depends on 2 factors:
1) preferred lifetime. http://tools.ietf.org/html/rfc4941#section-3.5 http://tools.ietf.org/html/rfc4941#section-3.5 for more info.
2) frequency of reconnection. Some platforms (iDevices in particular) decide to make a new the IPv6 address every time they reconnect. Great for privacy (And that's exactly how I ran the abovementioned networks, also take a look at the http://tools.ietf.org/html/draft-desmouceaux-ipv6-mcast-wifi-power-usage-00 http://tools.ietf.org/html/draft-desmouceaux-ipv6-mcast-wifi... for the observed leave/join stats), but if the infra does not have enough leeway to accomodate the extra addresses.
In any case even then not all is lost - clear the "A" bit in the RA to turn off the SLAAC, and use DHCPv6. Poor Android clients will be off the IPv6 grid because they don't bother to implement IPv6 for the reasons left unnamed here, but the rest of the gear will work just fine, with a single, predictable address, that an admin controls.
So, again - it all depends on the local situation and there's no unsolvable problems. There are existing and production-proven solutions.
- ysleepy 12y agoYou imply that DHCPv6 allows admin control, but as I understand it, it is not guaranteed that the request (DUID) can be mapped to a known device (MAC) (Type 1 DUID). Especially with installation media, it is just not feasible to custom script them to force Type1 usage. This makes bringup and configuration mgmt just rely on IPv4 to get an identity. I'm running into difficulties with this in our campus deployment. - I need static addresses in DNS (DDNS is just dirty, especially with DNSSEC) and also reverse records for kerberos. IPv6 just bums me out.
- ay 12y agoCan you use the UUIDs ? If you talk install, then with most of today's PXE ROMS first thing you want to do is to bootstrap into iPXE to get IPv6 support. That gives you also the support for pulling in your install via HTTP, with passing the UUID via the parameter in the boot URI. You can then drag this parameter all the way to the final boot of the client. I've done a PoC for a zero-touch install setup where you boot up a fresh empty machine and after a while of unattended magic it ends up with the Ubuntu installed and configured to a hostname set to its UUID. The address is registered via DDNS but not direct from the client - it's done via call-home server. IPvFoo independent and no need to tag to MAC address or any address family whatsoever. I've a 20-page write-up draft with scripts and all, though needs a ton more polishing for the real world. If it's of use to you, drop me an email, I can send - would be interesting to hear your opinion on that.
- techdragon 12y agoI spent a few days designing a thing like this for server deployment, but it was merely pen and paper notes, I would love to read through the draft you've written.
- ay 12y agoCouldn't find your email in profile - drop me an email at ayourtch at gmail / cisco dot com. It's too raw to just be dumped on the web, and I'd be curious to hear from a few folks doing this as a "day job" about the usefulness if I were to invest more time in it.