On Tue, Aug 21, 2018 at 1:23 AM Andy Smith <a...@strugglers.net> wrote: > > Hi Martin, > > On Mon, Aug 20, 2018 at 03:58:36PM +0300, Martin T wrote: > > On Mon, Aug 20, 2018 at 7:55 AM Andy Smith <a...@strugglers.net> wrote: > > > Back in 2011 this was a hard-won battle: > > > > > > > > > http://strugglers.net/~andy/blog/2011/09/04/linux-ipv6-router-advertisements-and-forwarding/ > > […] > > > Thanks for this very informative blog post! However, setting the > > "net.ipv6.conf.all.forwarding" to 1 in /etc/sysctl.conf and > > "accept_ra" to 2 in /etc/network/interfaces for ISP facing > > interface(eth0) didn't work for me. I expected SLAAC to work, but it > > didn't. I'm running kernel version 4.9.0. > > Strange. I've had a look and it seems I continued to use the > workaround mentioned in the blog post even though supposedly I no > longer need to. If you use that workaround, does it (SLAAC) start > working for you? > > Also, is it just address assignment that doesn't work or is it also > default router assignment that doesn't work? On my servers that > forward v6 I don't use dynamic assignment of addresses, I statically > assign them, but I do use dynamic assignment of default route. > > Cheers, > Andy >
Hi Andy, Thanks for your reply! > If you use that workaround, does it (SLAAC) start working for you? Do you mean the pre-up statements in /etc/network/interfaces? If yes, then with those workarounds the SLAAC works, i.e I get the default route. My ISP-facing interface is eth0 and it has forwarding disabled: # cat /proc/sys/net/ipv6/conf/eth0/forwarding 0 # Rest of the options are set: # cd /proc/sys/net/ipv6/conf/ # cat default/forwarding 1 # cat all/forwarding 1 # cat eth0/accept_ra 2 # cat all/accept_ra 1 # cat default/accept_ra 1 # However, I quite do not understand how returned IPv6 traffic(ingress traffic to eth0) is routed to my LAN-facing interface when I have disabled it in /proc/sys/net/ipv6/conf/eth0/forwarding? If I do the same for IPv4 traffic(echo 0 > /proc/sys/net/ipv4/conf/eth0/forwarding), then returned traffic is dropped because forwarding for eth0 is disabled. In addition, "accept_ra" with a value of 2 should ensure that RA messages are accepted even if forwarding for that interface is enabled, shouldn't it? > Also, is it just address assignment that doesn't work or is it also > default router assignment that doesn't work? On my servers that > forward v6 I don't use dynamic assignment of addresses, I statically > assign them, but I do use dynamic assignment of default route. I have exactly the same case. I use dynamic assignment only for default route and this doesn't work even if "accept_ra" has a value of 2. thanks, Martin
