IPv6 Loopback/Point-to-Point address allocation

Sun Sep 10 11:25:04 UTC 2017

On 10 September 2017 at 13:56, Thomas Bellman <bellman at nsc.liu.se> wrote:

> An alternative is to just have link-local addresses on your point-to-
> point links.  At least on your internal links where you run your IGP.
> On external links, where you run eBGP or static routes, it's probably
> more trouble than it is worth, though, since link-local addresses can
> change if you replace the hardware, requiring a config change on the
> other end.  (Also, I'm not sure all BGP implementations support using
> link-local addresses.)

This is solvable problem. Vendors support 'bgp listen' or 'bgp allow'
to accept BGP session from specific CIDR range. Similarly you could
allow IPv6 on interface, with SADDR anywhere in link-local. Your own
end link-local stability you could guarantee by manually configuring
MAC address, instead of using BIA. I.e. customers would experience
stable DADDR, but we wouldn't care about customer's SADDR.

However I don't think market would generally appreciate the
implications linklocal brings to traceroute, where least bad option
would be just to originate hop-limit exceeded from loop0, with no
visibility on actual interface.

-- 
  ++ytti