IPv6 Auto Discovery

[Doug Hardie]

On Jul 11, 2008, at 05:47, Steve Bertrand wrote:

> Doug Hardie wrote:
>> Mac OS-X does a form of auto discovery on IPv6 where the machines  
>> on a local network add the machine name to the ndp table when they  
>> see activity from that machine.
>
> ...FreeBSD does this as well (Neighbor Discovery).
>
> pearl# ndp -a
> Neighbor		Linklayer Address  Netif Expire    S Flags
> lanx.eagle.ca		0:b:46:3e:f3:41     fxp0 23h59m41s S R
> vandetta.ibctech.ca	0:f:b5:80:58:77     fxp0 15s       R
> v6.ibctech.ca		0:e:c:6c:e9:62      fxp0 permanent R
> v6.ibctech.ca		0:e:c:6c:e9:62      fxp0 permanent R
> ...etc, etc.
>
> If you don't have DNS configured, or you do not have reverse DNS  
> entries for the host IPs you are talking to, then only the IP will  
> be listed above.
>
>> So far I only have a rudimentary IPv6 configuration on FreeBSD 7  
>> running and it only sees the IP address, and then only after I ping  
>> the other end.
>
> What you see above is normal functionality of the IPv6 Neighbor  
> Discovery Protocol (RFC-4861). The 'neighbor cache' only gets  
> populated with entries when IP communication takes place, or you  
> receive/accept a router advertisement with a list of prefixes (ndp - 
> p).
>
> The fact that names are not appearing is due to (mis|non)  
> configuration of DNS either for the resolver on the box itself, or  
> reverse DNS missing for the LAN IPs as stated above.
>
> To add a DNS server in FreeBSD, simply:
>
> # echo "nameserver ip.of.name.server" >> /etc/resolv.conf
>
>> I couldn't find anything in /etc/defaults that seems to address  
>> auto discovery.  Is this something I have missed or what?
>
> Perhaps you are referring to 'Auto Configuration' (RFC-4862)?  
> Neighbor Discovery and Auto Configuration perform different tasks,  
> but the former is required by the latter.
>
> Can you describe exactly what you want to achieve? Is it only the  
> name resolution problem you described above?

I originally thought it was a DNS issue also.  There is no DNS server  
on the network.  However, that doesn't seem to bother the Macs as they  
quickly pick up the names of the machines and disseminate them to each  
other without a DNS server.  This is a test setup and systems come and  
go frequently.  I don't want the hassle of having to maintain a DNS  
server that would require modes several times a day.