[ale] IPv6 interface identifiers

[Jeremy T. Bouse]

On 08/16/2012 01:41 PM, mike at trausch.us wrote:
> Perhaps someone could explain something to me:  why are interface
> identifiers required for link-local communications, particularly on a
> system that has only a single network interface?
> 
> e.g., I have a router that is using the address fe80::c9f:e0ff:fef1:ae2a
> on my network.  The system I am on uses fe80::6e62:6dff:fe53:103.  But
> if I want to reach the router by SSH, I must either SSH to its public
> address, or I must do this:
> 
> ssh fe80::c9f:e0ff:fef1:ae2a%eth0
> 
> Or I get an "invalid argument" error.
> 
> The fact that I have only one interface shouldn't matter.  I thought
> IPv6 ND made it possible to hide exactly this sort of detail.
> 
> 	--- Mike
> 
	Are both machines on the same physical network segment? I mean are the
both wired or both wifi? the LL IPv6 interface addresses are meant for
communication only on the same physical layer. My entire network here is
dual-stacked and I've never had to specify the interface identifier.
I've been working with IPv6 since '01 when I was working for NTT MCL
back in CA.