IPv6 DHCP and static address

Hi...

I did give my server a static IPv6 address and, it's running a DHCPv6 server
on it... but, the server still get's an additional IPv6 address from this
DHCP ... why? (and it is also entering this address into the dns server...
this leads to problems, if a server has more than one address and if it
might change it's address one day... so, I don't want it to get an other
address than the static one... there's no need for a second one...)

Rudolf

 

Hello Rudolf,

Sounds for me that the hardware has 2 NICs and the unused one is not disabled.

Best regards

Meinolf Weber

 

Hi

It has even more than 2 NICs... but I have all NICs under controll, except
the one that has IPv6 enabled... this NIC has 3 IPs (v6) ... an fe80, an
fd00 -> the static one I set... and, an other fd00 that it got from the DHCP
which is responding on the static IPv6 address of this interface...

Rudolf

 

Is this server a domain controller?

Does it have RRAS installed? If so, that can be where the additional IP is
coming from.

Ace

 

Hi

Yes... but why a second one on that interface? ... *hmm* but you're right...
I remeber, that I heart something like that before... I'll try to find out
more... thanks

Rudolf

 

Hi Rudolf,

RRAS pulls a block of 10 IPs at a time from DHCP. It will register into DNS
with the IPs it gives a client machine connecting to it under the server's
name. This is problematic for AD, which is why we recommend against using
RRAS on a DC. If you want to continue using RRAS on the DC, please read the
following on how to control DNS registration wtih the additional IPs that
incur from RRAS. Keep in mind it requires registry changes to the Netlogon
registry key to control it. This key is what registers data into DNS on a
domain controller, not the actual interface.

Multihomed DCs with DNS, RRAS, multiple IPs, and/or PPPoE adapters
http://msmvps.com/blogs/acefekay/ar...-dcs-with-dns-rras-and-or-pppoe-adapters.aspx

Ace

 

Hi

ok... I don't know if this is a problem at the moment, because IPv6 RAS is
disabled... but, other question now... does SBS not include all those roles?
and do they not run on the same machine?

anyway... thank's for the link... that's for shure something I'll have to go
through... I know... but I didn't find the link anymore

about the initial problem... I think this has to do with the stateless and
statefull configuration of the interface... but... I will first have to read
some documents until I can say more...

Rudolf

 

AHHHH, I should have asked which version of the operating system you are
running. If I knew it was SBS, I wouldn't have posted that link, and I would
have redirected you to post to the SBS newsgroup. SBS is different. Wizards
will handle most of the configurations for you. I cross-posted it so my
current reply will go to both this group and the SBS group where those folks
are better equipped to answer your questions.

Original question:

Hi...

I did give my server a static IPv6 address and, it's running a DHCPv6 server
on it... but, the server still get's an additional IPv6 address from this
DHCP ... why? (and it is also entering this address into the dns server...
this leads to problems, if a server has more than one address and if it
might change it's address one day... so, I don't want it to get an other
address than the static one... there's no need for a second one...)

Rudolf





Ace

 

AHHHH, I should have asked which version of the operating system you are

Hi

Sorry for this missunderstanding but... I'm not running SBS... I was just
wondering, how they do it on SBS... ... but now it's clear... so, SBS is
not just a "normal" server, but a server with special wizards and
assistants... very interesting... and... a bit strange... but, that's how
Microsoft seems to solve those problems... first create them and then create
a registry hack and sell it as SBS

.... again... I'm currently investigating those configuration modes of IPv6
that are available... and, I'll post it here if I can find out something...

Rudolf

 

Oh, I assumed you meant this was SBS. My bad for the assumption.

I wouldn't exactly say they are registry hacks put together and sold as SBS,
nor is it strange. It's not like that. It's an optimized package based on
Standard Server edition for small entities. It has limitations due to the
additional products (SQL, Exchange, ISA, etc), offered in one package for
the low prices that it sells for compared if you were to purchase the
products separately, as well as designed to run on one server.

As far as IPv6, it works the same on SBS and non-SBS. IPv6 is IPv6.

If the DNS address you are getting is ::1, that is put in from dcpromo when
promoting a machine to a DC. I usually delete that out, or more
specifically, disable IPv6 completely because most of my customers are small
to medium size infrastructures and do not have the equipment in place to
handle IPv6.

My feeling about IPv6 is that to completely support it, routers in the
infrastructure need to support it, as well as other machines to fully gain
any benefits. I've seen scenarios where IPv6 is used in a backbone (such as
in a BGP scenario in a large university) and handled between routers,
however the local client subnets are all IPv4. So since I am not in that
scenario with my small to medium sized customers, I simply disable it.

Ace

 

::1 is the IPv6 loopback address, and just means "use the local machine",
just like 127.0.0.1 in IPv4.

 

I kind of figured that because I know from past experience that dcpromo puts
that in there, just as in 2003 putting in the loopback. Thanks for
confirming that!

Ace