Site Link Bridges - Do I need them?

Hello, thank you for visiting my question...

I have a total of 9 offices.  I have site to site VPN's connecting all 8 branch offices to the corporate office.  No site to site VPN's between branch offices (So the enterprise network is not fully routed)

A - Corporate Office (
B - Branch1 (
C - Branch2 (
D - Branch3
E - Branch4
F - Branch5
G - Branch6
H - Branch7
I - Branch8

Currently... 2 out of 8 branch offices have joined the corporate domain and I have configured my sites and services as follows:

Site Links:

Site Link Bridges:

All subnets are in place and everything is working like a charm.  You know what that means... time to break something!

Lets say I want to join the remaning 6 branch offices to the corporate domain.  Are there three ways to do it?

1) Create 28 additional site to site VPN's to make the enterprise network fully routed.  This way I will not need to create any site link bridges. (Not preferred - too costly?)

2) Forget the additional VPN's and create 28 Site Link bridges (AD Replication may be too slow?)

3) Forget the VPN's and the Site Link Bridges and just create 8 site links? A-B,  A-C,  A-D,  A-E,  A-F,  A-G,  A-H,  A-I (this is my question...)

Do I need all the site link bridges?  Will AD Replication work as it should without them?  If I do need them, would it be in my best interest to make the network fully routed?


Who is Participating?
Casca1Connect With a Mentor Commented:
Only if you wanted redundancy. You do not HAVE to have bridges. They are created by default, I believe, but are not required. By setting site A as the hub and scheduling the replication intervals, you can keep your AD up to date, if not the MOST current configuration that way. The only way to ensure the most current information would be to have a mesh, obviously.
You need the site links. I can't remember if site link bridging is automatic. You do not, however, need the site link bridge. You obviously not what site link bridges are, but they enable sites to do pass throughs to another (Bridged) site.
I think bridging may be automatic, to provide for fault tolerance.
Joe_CAuthor Commented:
Correct me if I'm wrong...

Because my network is not fully routed I had to uncheck the "Bridge All Site Links" checkbox and then create the AB-AC site link bridge.  It appears that if I do not configure it this way I get errors due to B and C not being able to communicate with eachother.
Free Tool: ZipGrep

ZipGrep is a utility that can list and search zip (.war, .ear, .jar, etc) archives for text patterns, without the need to extract the archive's contents.

One of a set of tools we're offering as a way to say thank you for being a part of the community.

No, I will not correct you. You are right. 8-)
In this type of environment, you will want to create the site links manually as you did with the A-B and A-C links.
Hehe; Sorry; I just woke up.. A little bleary. I keep thinking of things after I submit.
In this situation, I would set it up as a hub and spoke pattern, with what appears to be your Site A as the primary site. Then set replication traffic to suit.
Joe_CAuthor Commented:
OK... lets say I have site A at the top and then from left to right sites B through I


* * * * * * * *
B C D E  F  G  H  I

This is what I know for sure:

I would need 8 site links (from site A to each branch office)

This is what I'm unsure of:

What site link bridges would I need to create?  Would I need 28 of them to accomidate every possible path?

Thanks Again!!
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

All Courses

From novice to tech pro — start learning today.