cannot renew IPV6 address

Bjørn Mork bjorn at
Sat Jan 28 15:17:22 UTC 2017

Jean-Max Reymond <jmreymond at> writes:

> # tcpdump -i eno1 -vv ip6|head -10
> tcpdump: listening on eno1, link-type EN10MB (Ethernet), capture size
> 262144 bytes
> 19:36:23.877024 IP6 (hlim 1, next-header UDP (17) payload length: 52)
> fe80::250:56ff:fe00:d633.dhcpv6-client > ff02::1:2.dhcpv6-server: [udp
> sum ok] dhcp6 solicit (xid=f24d5e (client-ID hwaddr/time type 1 time
> 514053608 000c2983d6d2) (elapsed-time 0) (IA_PD IAID:4 T1:0 T2:0))


> # cat /var/db/dhclient6.leases
> default-duid "\000\001\000\001 \033\313$T\2375\007\255\030";
> lease6 {
>  interface "eno1";
>  ia-pd 35:07:ad:18 {
>    starts 1485445025;
>    renew 43200;
>    rebind 172800;
>    iaprefix 2001:bc8:344f:200::/56 {
>      starts 1485445025;
>      preferred-life 7200;
>      max-life 43200;
>    }
>  }
>   option dhcp6.client-id 0:3:0:1:73:41:e0:29:71:a3;
>   option dhcp6.server-id 0:1:0:1:1b:ac:bc:2d:10:60:4b:9b:a:f4;
>   option 2001:bc8:401::3,2001:bc8:1::16;
>   option dhcp6.domain-search "";
> }

The tcpdump output is hard to read (use tshark -V instead...), but IIUC
you show us two very different requests here.  The client DUID and IA_PD
IAID are both different.  Your ISP might have a one prefix per circuit
limit, causing requests from any but the first client on a circuit to be
silently ignored.

And you have also not shown us how you use the allocated prefix, making
it impossible to know if the error is in the DHCP transaction or in your
local address assignment policy. Receiving an IA_PD prefix will not
magically provide you with any IPv6 connectivity.  You'll need to split
it up and assign it to interfaces.  And you will need to set up routing
as well, possibly using a default route from an RA.


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