Thank you very much for the reply, Kirill. > > try with > > > > route add -inet6 2001:db8:efef::1 -llinfo -link -static -iface vio0 > > ... that is, try the above before you try to add 2001:db8:efef::1 as > default gateway.
I already tested something similar in my previous attempts with flags and link, but it also didn't work. Here's how it behaves, when I use the exact command you've advised. I removed all previous IPV6 addresses and flushed all routes before testing. $ ifconfig vio0 inet6 2001:db8:efef:aaaa:d9e:18d2:b761:0/121 $ route add -inet6 2001:db8:efef::1 -llinfo -link -static -iface vio0 add host 2001:db8:efef::1: gateway vio0 $ route -n show -inet6 Routing tables Internet6: Destination Gateway Flags Refs Use Mtu Prio Iface ::1 ::1 UHl 0 20 32768 1 lo0 2001:db8:efef::1 link#1 UHLS 0 1 - 8 vio0 2001:db8:efef:aaaa:d9e:18d2:b761:0/121 2001:db8:efef:aaaa:d9e:18d2:b761:0 UCn 0 0 - 4 vio0 2001:db8:efef:aaaa:d9e:18d2:b761:0 62:86:db:bc:c6:74 UHLl 0 0 - 1 vio0 ... $ ping6 2001:db8:efef::1 PING 2001:db8:efef::1 (2001:db8:efef::1): 56 data bytes ping6: sendmsg: Invalid argument ping: wrote 2001:db8:efef::1 64 chars, ret=-1 At this point 2001:db8:efef::1 is inaccessible with normal ping, so it shouldn't work as a default gateway. But nevertheless I've tried that. $ route add -inet6 default 2001:db8:efef::1 add net default: gateway 2a02:25b0:aaaa::1 $ ping6 www.google.com PING www.google.com (2a00:1450:4014:80a::2004): 56 data bytes ping6: sendmsg: Invalid argument ping: wrote www.google.com 64 chars, ret=-1 So unfortunately adding a route this way also doesn't work. Thank you, Michal