IPv6 migration steps for mid-scale isp

Thu Sep 14 22:58:35 UTC 2017

We are small but we are just about out of IPv4 and aren't going to get
or buy any more. We have been testing for a while.

> Shall I go for IPv6-only deployment or dual stack?

You should plan for adding customers eventually that are IPv6-only,
unless you have all the v4 you will ever need, and you will need to
reserve IPv4 address blocks for translation.

> How to identify address CPE and legacy application issues?

Legacy application issues can be solved (for the most part) with
464XLAT, which also solves IP-literal-in-HTML problems. You need PLAT at
the core and CLAT at the client. Unfortunately so far the only good way
we've found to do CLAT is OpenWRT on the CPE or router. We are getting
ready to bundle Linksys routers flashed with OpenWRT.

For PLAT at the core we are running jool. It's actually quite simple to
set up and we are currently using OSPF to do anycast, but we will
probably be migrating to a single set of HA servers in the core. The
good news is that even if it goes down, Netflix and Facebook will still
work as they are fully functional on v6.

We have tested this in my home and at my office with IPv6-only
VLANs/wireless SSIDs, mostly without a hitch.

If you run this setup without the CLAT on the client side you get NAT64
so it still will work for most things.

I would be very, very happy if larger ISPs would put pressure on router
manufacturers to support CLAT, we have no clout. I would also love to
hear if any of this is stupid or if there's a better way.

--Brock