How to stop two servers in different sites trying to replicate with each other

[Curtis Fray]

Hi,

I have a Windows 2003 network running in 2003 native mode. I have three
sites definied under ADSS. Site A is the main site with the bulk of the
servers. I have a single DC located in Site B and another single DC located
in Site C. Because of how routing is configured, Site B can not communicate
directly with Site C and vice versa. However, both sites can communicate
with Site A. What I'm finding is under the NTDS settings in ADSS the DC in
Site B keeps setting up one of its replication partners to be the DC in Site
C, and the DC in Site C is trying to replicate with the DC in Site B. This
is causing errors to crop up in their event viewers where this direct
communication isn't possible. It's not causing major problems as they're
still both connected to DCs in Site A.

I've tried manually deleting the replication partners I know can't
communicate, and I've also tried manually changing the "replicate from
partner" in the ones that are automatically assigned. But after a few hours
they keep getting automatically re-added. Is there anyway I can override
this?

Thanks,

Curtis.

 

[Jmnts]

Hi

I have a Windows 2003 network running in 2003 native mode. I have three
sites definied under ADSS. Site A is the main site with the bulk of the
servers. I have a single DC located in Site B and another single DC
located in Site C. Because of how routing is configured, Site B can not
communicate directly with Site C and vice versa. However, both sites can
communicate with Site A. What I'm finding is under the NTDS settings in
ADSS the DC in Site B keeps setting up one of its replication partners to
be the DC in Site C, and the DC in Site C is trying to replicate with the
DC in Site B. This is causing errors to crop up in their event viewers
where this direct communication isn't possible. It's not causing major
problems as they're still both connected to DCs in Site A.

If Site B and Site C can reach Site A why dont't you set up routing tables
so that Site B can reach Site C through Site A and Vice versa?

I've tried manually deleting the replication partners I know can't
communicate, and I've also tried manually changing the "replicate from
partner" in the ones that are automatically assigned. But after a few
hours they keep getting automatically re-added. Is there anyway I can
override this?

The connection objects are being created automaticaly for you. (That's the
default behavior - KCC for intrasites, then KCC selects one server to be
ISTG for intersites connections using BH)

Before you do this you should consider the options that you have so I
recommend you to check:
1Option
- The routing tables already mentioned ( If Site B and Site C can reach Site
A why dont't you set up routing tables so that Site B can reach Site C
through Site A and Vice versa?)

2nd Option (If the 1st Option don't work for you)
- If you don't want that Kcc/ISTG creates Automatically connections between
Site B and Site C, all you need to do is to disable transitivity between
sites.
Site Link Transitivity: By default, all site links are transitive, which
simply means that if sites A and B are linked and sites B and C are linked,
then site A and site C are transitively linked. To disable Site link
transitivity go to Inter-Site Transports -> Right click IP -> Uncheck the
option Bridge All Sites links.

Then what you need to to is
Create a Site link between Site A and B
Create a Site link between Site A and C

Because sites aren't transitive (because we unchecked the option Bridge All
Sites links), the ISTG won't use the BH servers between Site C and SiteB to
create connections objects between them.

force replication in all sites, and then if you want to see the results,
right click on NTDS settings in each server and choose All tasks -> Check
replication topology. Then refresh the sites and you should see that no
connections will be available between Site B and SiteC.

3th Option (If Opt 1 and 2 don't apply - I strongly not recommend this one)

To disable KCC from creating connections:

How to disable the Knowledge Consistency Checker inter-site topology
generation for all sites
http://support.microsoft.com/default.aspx?scid=kb;en-us;245610
How to disable the Knowledge Consistency Checker from automatically creating
replication topology
http://support.microsoft.com/default.aspx?scid=kb;en-us;242780

Be careful with disable KCC because you'll need to create manually the
connections objects. You must define the BH between Servers, and if the BH
fails and you didn't selected an alternative, the replication will fail.
This also apply when you manually select BH servers on sites even if the Kcc
is running)

 

[Curtis Fray]

Thanks for the quick reply. I'll have a look into the options you suggest.
And yes, I agree option 3 isn't the way to go!

Regards,

Curtis.
--

Hi

I have a Windows 2003 network running in 2003 native mode. I have three
sites definied under ADSS. Site A is the main site with the bulk of the
servers. I have a single DC located in Site B and another single DC
located in Site C. Because of how routing is configured, Site B can not
communicate directly with Site C and vice versa. However, both sites can
communicate with Site A. What I'm finding is under the NTDS settings in
ADSS the DC in Site B keeps setting up one of its replication partners to
be the DC in Site C, and the DC in Site C is trying to replicate with the
DC in Site B. This is causing errors to crop up in their event viewers
where this direct communication isn't possible. It's not causing major
problems as they're still both connected to DCs in Site A.

If Site B and Site C can reach Site A why dont't you set up routing tables
so that Site B can reach Site C through Site A and Vice versa?

I've tried manually deleting the replication partners I know can't
communicate, and I've also tried manually changing the "replicate from
partner" in the ones that are automatically assigned. But after a few
hours they keep getting automatically re-added. Is there anyway I can
override this?

The connection objects are being created automaticaly for you. (That's the
default behavior - KCC for intrasites, then KCC selects one server to be
ISTG for intersites connections using BH)

Before you do this you should consider the options that you have so I
recommend you to check:
1Option
- The routing tables already mentioned ( If Site B and Site C can reach
Site A why dont't you set up routing tables so that Site B can reach Site
C through Site A and Vice versa?)

2nd Option (If the 1st Option don't work for you)
- If you don't want that Kcc/ISTG creates Automatically connections
between Site B and Site C, all you need to do is to disable transitivity
between sites.
Site Link Transitivity: By default, all site links are transitive, which
simply means that if sites A and B are linked and sites B and C are
linked, then site A and site C are transitively linked. To disable Site
link transitivity go to Inter-Site Transports -> Right click IP -> Uncheck
the option Bridge All Sites links.

Then what you need to to is
Create a Site link between Site A and B
Create a Site link between Site A and C

Because sites aren't transitive (because we unchecked the option Bridge
All Sites links), the ISTG won't use the BH servers between Site C and
SiteB to create connections objects between them.

force replication in all sites, and then if you want to see the results,
right click on NTDS settings in each server and choose All tasks -> Check
replication topology. Then refresh the sites and you should see that no
connections will be available between Site B and SiteC.

3th Option (If Opt 1 and 2 don't apply - I strongly not recommend this
one)

To disable KCC from creating connections:

How to disable the Knowledge Consistency Checker inter-site topology
generation for all sites
http://support.microsoft.com/default.aspx?scid=kb;en-us;245610
How to disable the Knowledge Consistency Checker from automatically
creating replication topology
http://support.microsoft.com/default.aspx?scid=kb;en-us;242780

Be careful with disable KCC because you'll need to create manually the
connections objects. You must define the BH between Servers, and if the BH
fails and you didn't selected an alternative, the replication will fail.
This also apply when you manually select BH servers on sites even if the
Kcc is running)