On 2019-11-28 04:11, Ralph Seichter wrote: > > But what about connecting to the outside world? For that, the > > link-local address doesn't work. > > It does work, actually. fe80::1 is a perfectly valid way to specify the > default gateway. Remember that NICs have several IPv6 addresses with > different scopes.
Sorry, I'm still confused :-( My host has to set the source address field in outgoing packets to something. If it's the link local address the router can't just forward it unmodified, or upstream routers and hosts won't know where it originally came from. What am I missing? wikipedia: In a computer network, a link-local address is a network address that is valid only for communications within the network segment or the broadcast domain that the host is connected to. As for fe80::1 being good as it is ... matica!8 lc$ route -6 Kernel IPv6 routing table Destination Next Hop Flag Met Ref Use If localhost/128 [::] Un 0 2 0 lo fe80::52e5:49ff:fec0:504d/128 [::] Un 0 3 0 enp2s0 fe80::/64 [::] U 256 2 0 enp2s0 ff00::/8 [::] U 256 2 0 enp2s0 [::]/0 [::] !n -1 1 0 lo matica!9 lc$ ping -6 fe80::1 PING fe80::1(fe80::1) 56 data bytes >From fe80::52e5:49ff:fec0:504d%enp2s0: icmp_seq=1 Destination unreachable: >Address unreachable >From fe80::52e5:49ff:fec0:504d%enp2s0: icmp_seq=2 Destination unreachable: >Address unreachable >From fe80::52e5:49ff:fec0:504d%enp2s0: icmp_seq=3 Destination unreachable: >Address unreachable >From fe80::52e5:49ff:fec0:504d%enp2s0: icmp_seq=4 Destination unreachable: >Address unreachable >From fe80::52e5:49ff:fec0:504d%enp2s0: icmp_seq=5 Destination unreachable: >Address unreachable >From fe80::52e5:49ff:fec0:504d%enp2s0: icmp_seq=6 Destination unreachable: >Address unreachable ^C --- fe80::1 ping statistics --- 7 packets transmitted, 0 received, +6 errors, 100% packet loss, time 143ms pipe 3 matica!10 lc$ traceroute -6 fe80::1 traceroute to fe80::1 (fe80::1), 30 hops max, 80 byte packets connect: Invalid argument > > No configuration needed for this ULA thing? How does it happen, then - > > is it implemented entirely in the kernel? > > Before I try to come up with my own explanation, I suggest you search > for terms like Neighbor Discovery Protocol (NDP) and Stateless Address > Autoconfiguration (SLAAC). The latter, for example, is the reason why > DHCPv6 is often not necessary. Ok, I'll do that ... I wonder if those can give me a real address though. -- Please don't Cc: me privately on mailing lists and Usenet, if you also post the followup to the list or newsgroup. To reply privately _only_ on Usenet and on broken lists which rewrite From, fetch the TXT record for no-use.mooo.com.
