I struggled with this under CentOS 7. I think there is a bug. You can run /usr/sbin/radvdump to print out RAs. Leave it running for some minutes. I had this in my /etc/sysctl.d/50-net6.conf (on C7): # # IPv6 Forwarding # net.ipv6.conf.all.forwarding = 1 net.ipv6.conf.default.forwarding = 1 net.ipv6.conf.all.accept_ra = 1 net.ipv6.conf.default.accept_ra = 1 # # Fix bug to received RAs from Router # Disable forwarding on enp4s0f1 interface so we still get RAs # net.ipv6.conf.enp4s0f1.forwarding = 0 #net.ipv6.conf.enp4s0f1.accept_ra = 1 where enp4s0f1 is the WAN interface. Note that ipv6 forwarding still works. I used my C7 as a firewall/gateway. I am running 8.1 now. Alan -- Alan McRae On 29/04/2020 06:54, Kenneth Porter wrote: > I just got 50 Mbps symmetric fiber from AT&T and it includes a /56 of > IPv6 addresses, replacing a much slower ADSL line. I never tried to > get IPv6 working on the old connection. I'm using CentOS 7 as a > gateway and it's worked great for several versions for IPv4. > > I'm not seeing any IPv6 default route on the WAN interface. I suspect > I'm not getting route announcements. I think I have all the IPv6 > variables in ifcfg-em2 set right. But I do notice that the accept_ra > file in proc for that interface has value 1, not 2. Changing it to 2 > doesn't change anything, though. No route appears. > > While I wait for an answer to my trouble ticket, is there some way to > verify that I'm not receiving any RA packets? Is there a way to force > a solicitation for one? Is there a tcpdump invocation I can use to > watch for them? Are there log messages that will tell me when an RA > has been seen and added to the routing table or ignored? > > _______________________________________________ > CentOS mailing list > CentOS at centos.org > https://lists.centos.org/mailman/listinfo/centos