No available prefix prevents adress assignment?

Oskar Berggren oskar.berggren at
Tue Mar 27 14:49:41 UTC 2012


I have a problem assigning an IPv6 address to the WAN side of a router
that also attempts to request a delegated prefix. Is this by design?
Read on for details.

With server version 4.2.2 for DHCPv6. For this experiment I have
configured the network to use DHCPv6 for address assignment, not
SLAAC. I have not configured any prefix for prefix delegation in the
dhcp server.

I'm experimenting with a dhcp client in the form of a home router.
When it boots it
a) sends an RS message
a) determines from RA that it should use DHCPv6 for address assignment
b) sends a dhcpv6 solicit message, requesting some options, a
non-temporary address and a delegated prefix

At this stage the dhcpd server log contains the following information:
Mar 27 16:40:29 TEST dhcpd: Solicit message from
fe80::5a6d:8fff:fea0:2b4a port 546, transaction ID 0xBA86C400
Mar 27 16:40:29 TEST dhcpd: Picking pool address 2a01:5300:8:3f::8
Mar 27 16:40:29 TEST dhcpd: Unable to pick client prefix: no IPv6
prefix pools on this shared network
Mar 27 16:40:29 TEST dhcpd: Sending Advertise to
fe80::5a6d:8fff:fea0:2b4a port 546

The client never gets the assigned address. By looking at the packets,
I can verify that the DHCP server nevers sends the assigned address to
the client. The dhcpv6 advertise packet basically contains only the
NoAddrAvail error code.

Is this by design? Or a bug in ISC DHCPd?


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