DHCPV6 client/server netmask, default route

[helpmelearn]

Hi,
I have a Centos6 ISC 4.1.1 dhcpv6 server. The client is ubuntu lucid with both dibbler-dhcpv6 and wide-dhcpv6 clients installed.

The primary issue I am trying to solve is to get the dhcpv6 client learn the correct netmask when it gets the IP address from the dhcpv6 server.

I can get the dhcpv6 client to assign the server-supplied ipv6 address, but the netmask is fixed at /64 no matter how the server configuration file is.

The client's output:
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qlen 1000
inet6 fd1e:9b0f:2212:3028:223:9cff:fe26:f702/64 scope global
valid_lft forever preferred_lft forever
inet6 fe80::c4b0:a8ff:fee8:3a44/64 scope link
valid_lft forever preferred_lft forever


Server config:
authoritative;
update-static-leases off;
subnet6 fd1e:9b0f:2212:3028:223:9cff:fe00:0000/104 {
range6 fd1e:9b0f:2212:3028:223:9cff:fe26:f702 fd1e:9b0f:2212:3028:223:9cff:fe26:f702;
preferred-lifetime 36000;
}

I wish the client to know the netmask is /104, which is not happening with dibbler-client.

Is there any option I am missing? Any config error?

I even tried to get wide-dhcpv6 client -- but my ISC DHCPv6 server doesn't seem to be replying to dhcp solicit messages from wide-dhcpv6 client. While the same server replies just fine to dibbler-client (which then ends up with the netmask issue).

Any pointers? Any comments?

Thanks in advance!

[jpopelka]

Hi,

AFAICT DHCPv6 (RFC 3315) does not currently permit specification of a prefix length (something like subnet-mask option for DHCPv4).
Try to Google out "dhcpv6 prefix length" to get more info.

[helpmelearn]

Hi,

AFAICT DHCPv6 (RFC 3315) does not currently permit specification of a prefix length (something like subnet-mask option for DHCPv4).
Try to Google out "dhcpv6 prefix length" to get more info.

Hi there,
Thank you very much for correcting the search term I should have used. Searching for prefix length showed useful information like this thread:

w#w#w.mail-arc#hive#.c#om/ipv6@ietf.org/msg08187.html

... which clarifies a good deal of confusion. (To get to URL remove #, I am not allowed to post external links!)

Looks like RAs ARE required to send default router and prefix length information.

Could someone confirm that RADVD could be run on my local linux box to provide such information (default route, prefix length) to my (VM) client? How does RADVD interact with a real router upstream? Any relevant links would be great!

Again, thank you for the answer!