Setup IPv6

tested on Slackware Linux current (Sep 2020)

SLAAC

All you need is your kernel to listen to RAs

Accept Router Advertisements (default is 1)

0 -- Do not accept Router Advertisements
1 -- Accept Router Advertisements if forwarding is disabled
2 -- Overrule forwarding behaviour. Accept Router Advertisements even if forwarding is enabled

and eventually enforce them over forwarding (assuming xenbr0 is your public facing interface)

    echo 2 > /proc/sys/net/ipv6/conf/xenbr0/accept_ra

check

    cat /proc/sys/net/ipv6/conf/*/accept_ra
    cat /proc/sys/net/ipv6/conf/*/autoconf

DHCPv6

You still need SLAAC to be enabled here (see right above).

Then use a good DHCP client to tell your ISP about your DUID

vi /etc/dhclient6.conf

interface "xenbr0" {
    send dhcp6.client-id YOUR-DUID;
        #request;
}

Ready to go

enable SLAAC at boot-time

vi /etc/rc.d/rc.inet1

    echo IPv6 SLAAC
    echo 2 > /proc/sys/net/ipv6/conf/xenbr0/accept_ra

enable SLAAC + static IP at boot-time

vi /etc/rc.d/rc.inet1

    echo IPv6 SLAAC
    echo 2 > /proc/sys/net/ipv6/conf/xenbr0/accept_ra

    echo IPv6
/sbin/ifconfig xenbr0 inet6 add x::x/56 up

    echo -n DUID...
    /sbin/dhclient -cf /etc/dhclient6.conf -6 -P xenbr0 -v && echo done || echo FAIL

status

ifconfig
ps auxfww | grep dhclient

stop

ip addr del x::x/56 dev xenbr0
/sbin/dhclient -x -pf /var/run/dhclient6.pid
pkill dhclient

Acceptance

who’s your router

#netstat -rn --inet6 | grep ^::/0
ip -6 neigh show
ping6 ...

grab some advertisements from the network

tcpdump -vvvv -ttt -i xenbr0 icmp6 and 'ip6[40] = 134'

everything is good?

cat /etc/resolv.conf
ping6 2001:bc8:401::3
ping6 2001:bc8:1::16
ping6 ipv6.google.com
traceroute6 ipv6.google.com
curl -si www.kame.net | grep /img/kame

Become a router

see IPv6 RA router

Additional notes

Other means of enforcing RA over forwarding

    #sysctl -w net.ipv6.conf.eth0.accept_ra=2
    #echo net.ipv6.conf.eth0.accept_ra = 2 >> /etc/sysctl.conf
    #sysctl -p

To entirely disable IPv6 at boot time

disable_ipv6=1

and to disable IPv6 while the system is running

sysctl -w net.ipv6.conf.all.disable_ipv6=1
sysctl -w net.ipv6.conf.default.disable_ipv6=1

Resources

DebianIPv6 https://wiki.debian.org/DebianIPv6

For clients https://wiki.archlinux.org/index.php/IPv6#For_clients

6.2. Add an IPv6 address https://mirrors.deepspace6.net/Linux+IPv6-HOWTO/x1055.html

6.2. Add an IPv6 address https://linux.die.net/HOWTO/Linux+IPv6-HOWTO/x1054.html

Setup IPv6

SLAAC

DHCPv6

Ready to go

Acceptance

Become a router

Additional notes

Resources

dedibox

slaac

dhcpv6

disable ipv6

troubleshooting

acceptance

netbsd (untested)