Re: [v6ops] about LLAs pros/cons static routing - auto/self-configuration of addresses, draft-matthews-v6ops-design-guidelines

["Michael Behringer (mbehring)" <[e-mail]>]

> > Traceroute would work for you,
> 
> It shouldn't, because intermediate routers should discard ICMPv6 packets
> with LL source addresses, according to RFC 4291 section 2.5.6.
> 
> The fact that they don't is an implementation error, and we shouldn't rely
> on that. ICMPv6 should never be sourced from a LL address.

I can confirm that at least one implementation (ours) responds using a global address (from a loopback), not the link local. 

> 
>     Brian
> 
> however outside of your network, other people would be querying their
> own version of 0.8.e.f.ip6.arpa., hiding your interface and router names.
> This idea might be useful to assist with troubleshooting for a "Using Only
> Link-Local Addressing Inside an
> IPv6 Network" http://tools.ietf.org/html/draft-behringer-lla-only-01
> scenario.

The concern is that for ICMP echo reply, traceroute, etc the router will respond with a global address, which is a loopback address (in the absence of global addresses on the interface). You can therefore see the router, but not the interface (unless RFC5837 is implemented, which is generally not the case today). 

So I can't see how this helps troubleshooting? (I must be misunderstanding something here)

Michael