dhcpcd-discuss

Hi Timo,

On 5/27/19 10:20 PM, Timo Sigurdsson wrote:
> Bruce Schultz schrieb am 27.05.2019 12:41:
>
> > I'm getting the following line in my resolv.conf file after connecting
> > to my wifi. It seems like the interface name is appended after the ipv6
> > nameserver. DNS lookups have been failing
> >
> > nameserver fe80::a62b:b0ff:fea5:6f5c%wlp3s0
> This line is actually valid. The nameserver address is a link-local address. For such addresses, the system must know over which interface they should go as they aren't necessarily unique. You could have a wired connection and a wireless link active at the same time and on both networks this link-local address could exist, so the interface name is always appended to indicate over which interface a specific linkk-local address is to be used (even if you only have one interface). See also:
> https://en.wikipedia.org/wiki/IPv6_address#Scoped_literal_IPv6_addresses
>
> The address itself seems fine, too, since your latest Router Advertisements come from this address. So, if DNS lookups fail, I would check on the server side if the configuration is actually correct. You could try pinging the server to test IPv6 connectivity in gneral, check if the nameserver is actually listening on that interface on IPv6 as well or if a firewall rule prevents access.

That makes sense then. Every now & then my laptop fails to get a dhcp 
address. My usual solution is to reset the wifi access points. I suspect 
then that the IPv6 config is left over from those failed attempts; 
normally it doesn't get any IPv6 configuration when it works correctly. 
Is there any good explanation for why that router advertisement would 
not have been cleaned up afterwards?

Thanks for the explanation.

Bruce