DHCPDv6 and fixed hosts, not appearing in logs

[sillysausage]

On Mon, 16 Nov 2015 14:40:16 +0000
Patrick Trapp <ptrapp at nex-tech.com> wrote:

> I have yet to scratch the surface on IPv6 yet, but after reading
> through your post, I have a question: Have you confirmed that the
> dhcp request is reaching your server? I have seen reports of network
> devices that support IPv6, but not until it's turned on. Thought it
> would be worthwhile to ask if the traffic has been confirmed to be
> flowing before you try to change the traffic.
> 
> Patrick
>  

Yes, it most certainly works if I use SLAAC generated addresses or
statically set my interface on my workstation. I have full connectivity
when I do that.

I let my workstation get an IP through SLAAC, and then attempted to
run:

user at my_workstation:~ $ sudo dhcpcd -6
[sudo] password for user: 
DUID < DUID REMOVED >
eth0: IAID ff:ff:ff:ff
eth0: soliciting an IPv6 router
eth0: Router Advertisement from fe80::0db8:ffff:ffff:fff6
eth0: adding address 2001:0db8:1234:0001:ffff:ffff:ffff:2222/64
eth0: adding route to 2001:0db8:1234:0001::/64
eth0: adding default route via fe80::0db8:ffff:ffff:fff6
eth0: soliciting a DHCPv6 lease
timed out
forked to background, child pid 3086


gateway:~# tcpdump -i eth0 ip6 and udp

tcpdump: verbose output suppressed, use -v or -vv for full protocol
decode listening on eth0, link-type EN10MB (Ethernet), capture size
262144 bytes

IP6 fe80::ffff:ffff:ffff.546 > ff02::1:2.547: dhcp6 solicit
IP6 fe80::ffff:ffff:ffff.546 > ff02::1:2.547: dhcp6 solicit
IP6 fe80::ffff:ffff:ffff.546 > ff02::1:2.547: dhcp6 solicit
IP6 fe80::ffff:ffff:ffff.546 > ff02::1:2.547: dhcp6 solicit
IP6 fe80::ffff:ffff:ffff.546 > ff02::1:2.547: dhcp6 solicit
IP6 fe80::ffff:ffff:ffff.546 > ff02::1:2.547: dhcp6 solicit

the problem seems to be nothing going out from the DHCPDv6 server. The
DHCPDv6 server just isn't responding to the solicits from my
workstation. There is no firewall on my workstation, or otherwise
in between.

On Mon, 16 Nov 2015 15:37:06 +0000
Venkatesh Siddappa <Venkatesh.Siddappa at oneaccess-net.com> wrote:

> R u nunnig dhcpcd also.
> 
> from the below logs it is seen that
> ISC DHCP server running in v4 and v6 mode.
> 
> gateway:~# ps aux |grep dhcpd
> 
> 1686 dhcp  0:00 /usr/sbin/dhcpd -4 -cf /etc/dhcp/dhcpd.conf
>                                 -q -pf /var/run/dhcp/dhcpd.pid
>                                 -lf /var/lib/dhcp/dhcpd.leases
>                                 -user dhcp -group dhcp eth0
> 
> 1714 dhcp  0:00 /usr/sbin/dhcpd -6 -cf /etc/dhcp/dhcpdv6.conf
>                                    -q -pf /var/run/dhcp/dhcpdv6.pid
>                                    -lf /var/lib/dhcp/dhcpdv6.leases
>                                    -user dhcp -group dhcp eth0
> 

This is just from ps aux. I am running two instances of dhcpd because
one gives out IPv4 addresses, and the other gives out... or is supposed
to give out IPv6 addresses.

dhcpcd is also running on the router, as this is what gets the prefix
from my ISP.

I edited my /etc/radvd.conf and disabled AdvAutonomous, because I don't
want SLAAC generated IPs.

As to be expected then I get no IPv6 addresses, because DHCPDv6 isn't
sending anything back to my clients :(.