AD server subnet mask and default gateway change

[Guest]

I'm VLANing my network so I need to change default mask from 255.255.0.0 to
255.255.240.0 and default gateway from 172.16.1.1 to 172.16.0.1 on all of my
domain controllers (2 of them). Can I simply change it on the fly in network
connection properties? Any considerations?
Thank you.

 

[help]

The first two things that come into my mind are:

1- Have you created any sites? If so, remember to redefine the
Subnets on this sites (Active Directory Sites and Services) as you
will have a replication issue for sure. If you've got only the default
go ahead with number 2.
2- Once I happened this situation and my DCs had "burned" static
routes. Check out the persistent routes command lining "route print".

If you find out any other special consideration, please let me know.

Regards!

 

[Herb Martin]

I'm VLANing my network so I need to change default mask from 255.255.0.0
to
255.255.240.0 and default gateway from 172.16.1.1 to 172.16.0.1 on all of
my
domain controllers (2 of them). Can I simply change it on the fly in
network
connection properties? Any considerations?

Sure. As long as the DCs (and other machines) can route IP traffic they
will be fine
with these changes.

You might need to make appropriate entries in your AD Sites and Services
if you have Sites defined but your setup doesn't sound complicated enough
for you to have done that so far.

IF you change the IP of a DC, make sure you re-register them with DNS
using something like:

NetDiag /Fix

Restarting the "Netlogon" service usually works too

Or by restarting the DCs

 

[Guest]

Thanks a lot for your suggestions.
I have one site, I'm not sure if it is a default one but its name reflects
the office name so I'm assuming it was created. So under sites there are two
items: "site name" and subnets. Under "site name" ther are two DC and under
subnets - 172.16.0.0/16. If I go to properties of that subnet, the network
and mask are greyed out. Will the network and net mask change automatically
after I change it in the network properties for the NIC? How do I redefine
subnet?

Thank you.

 

[Herb Martin]

Thanks a lot for your suggestions.
I have one site, I'm not sure if it is a default one but its name reflects
the office name so I'm assuming it was created.

You are given one Site by default, Default-First-Site-Name but many
people just rename this when they get AD running.

So under sites there are two
items: "site name" and subnets. Under "site name" ther are two DC and
under
subnets - 172.16.0.0/16. If I go to properties of that subnet, the network
and mask are greyed out. Will the network and net mask change
automatically
after I change it in the network properties for the NIC? How do I redefine
subnet?

If you only have one site then you don't technically need any subnets
other than perhaps 0.0.0.0/0

Just make sure all your DCs and in the correct (only) site -- and if you
every start adding WAN Locations then remember to revisit the site
definitions first.

 

[Herb Martin]

Thanks a lot for your suggestions.
I have one site, I'm not sure if it is a default one but its name reflects
the office name so I'm assuming it was created. So under sites there are
two
items: "site name" and subnets. Under "site name" ther are two DC and
under
subnets - 172.16.0.0/16. If I go to properties of that subnet, the network
and mask are greyed out. Will the network and net mask change
automatically
after I change it in the network properties for the NIC? How do I redefine
subnet?

No, the Sites and Services "Subnets" have no connection to the DCs
or other server configuration.

YOU have to maintain that but with only one site it is trivial. Just
create a "subnet" BIGGER than all of your actual subnets such
as the one you seem to have.