Default route should be assumed from the RA when eth0 grabs its /128 (net.ipv6.conf.eth0.accept_ra_defrtr = 1)
What do you see in a tcpdump? Try this: tcpdump -vn -i eth0 icmp6 and ip6[40] == 134
vyos@vyos:~$ tcpdump -vn -i eth0 icmp6 and ip6[40] == 134
tcpdump: listening on eth0, link-type EN10MB (Ethernet), snapshot length 262144 bytes
17:26:05.443677 IP6 (hlim 255, next-header ICMPv6 (58) payload length: 144) fe80::201:5cff:fe7e:fe46 > ff02::1: [icmp6 sum ok] ICMP6, router advertisement, length 144
hop limit 0, Flags [managed, other stateful], pref medium, router lifetime 1800s, reachable time 3600000ms, retrans timer 1000ms
prefix info option (3), length 32 (4): 2001:558:4011:21::/64, Flags [none], valid time 604800s, pref. time 302400s
prefix info option (3), length 32 (4): 2001:558:5001:32::/64, Flags [none], valid time 604800s, pref. time 302400s
prefix info option (3), length 32 (4): 2001:558:6011:21::/64, Flags [none], valid time 604800s, pref. time 302400s
prefix info option (3), length 32 (4): 2001:558:8000:49::/64, Flags [none], valid time 604800s, pref. time 302400s
Also I think by default forwarding and accept_ra settings are already configured and all of that works out of the box, no need to fiddle with sysctl. Here’s my eth0 config and it just works. (1.4-rolling-202306190317)
eth0 conf
ethernet eth0 {
address dhcp
address dhcpv6
description "Comcast 1.25Gb/40Mb"
dhcpv6-options {
pd 0 {
interface eth1.200 {
address 1
sla-id 0
}
length 56
}
}
hw-id 00:21:70:d8:fa:51
}
[edit]
vyos@vyos# run sh int ethernet eth0
eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
link/ether 00:21:70:d8:fa:51 brd ff:ff:ff:ff:ff:ff permaddr 1c:83:41:32:d3:ba
inet 76.97.***.***/21 brd 255.255.255.255 scope global dynamic eth0
valid_lft 294060sec preferred_lft 294060sec
inet6 2001:558:6011:21:****:****:****:****/128 scope global
valid_lft forever preferred_lft forever
inet6 fe80::221:70ff:fed8:fa51/64 scope link
valid_lft forever preferred_lft forever
Description: Comcast 1.25Gb/40Mb
RX: bytes packets errors dropped overrun mcast
34751309079 83863617 0 0 0 81579
TX: bytes packets errors dropped carrier collisions
35267762818 73055710 0 0 0 0
[edit]
vyos@vyos# ip -6 r | match default
default via fe80::201:5cff:fe7e:fe46 dev eth0 proto ra metric 1024 expires 1797sec pref medium
default via fe80::ea9f:80ff:fea5:6a2f dev eth1 proto ra metric 1024 expires 1774sec hoplimit 64 pref medium
default via fe80::ea9f:80ff:fea5:6a2f dev eth1.100 proto ra metric 1024 expires 1719sec hoplimit 64 pref medium
[edit]
sysctl partial dump
vyos@vyos# sysctl -a | grep 'ipv6.*eth0\.'
sysctl: permission denied on key 'kernel.cad_pid'
sysctl: permission denied on key 'kernel.usermodehelper.bset'
sysctl: permission denied on key 'kernel.usermodehelper.inheritable'
net.ipv6.conf.eth0.accept_dad = 1
net.ipv6.conf.eth0.accept_ra = 2
net.ipv6.conf.eth0.accept_ra_defrtr = 1
net.ipv6.conf.eth0.accept_ra_from_local = 0
net.ipv6.conf.eth0.accept_ra_min_hop_limit = 1
net.ipv6.conf.eth0.accept_ra_mtu = 1
net.ipv6.conf.eth0.accept_ra_pinfo = 1
net.ipv6.conf.eth0.accept_ra_rt_info_max_plen = 0
net.ipv6.conf.eth0.accept_ra_rt_info_min_plen = 0
net.ipv6.conf.eth0.accept_ra_rtr_pref = 1
net.ipv6.conf.eth0.accept_redirects = 0
net.ipv6.conf.eth0.accept_source_route = -1
net.ipv6.conf.eth0.accept_untracked_na = 0
net.ipv6.conf.eth0.addr_gen_mode = 1
net.ipv6.conf.eth0.autoconf = 0
net.ipv6.conf.eth0.dad_transmits = 1
net.ipv6.conf.eth0.disable_ipv6 = 0
net.ipv6.conf.eth0.disable_policy = 0
net.ipv6.conf.eth0.drop_unicast_in_l2_multicast = 0
net.ipv6.conf.eth0.drop_unsolicited_na = 0
net.ipv6.conf.eth0.enhanced_dad = 1
net.ipv6.conf.eth0.force_mld_version = 0
net.ipv6.conf.eth0.force_tllao = 0
net.ipv6.conf.eth0.forwarding = 1
net.ipv6.conf.eth0.hop_limit = 64