Correct, site links do represent the physical networking relationship
between two sites. As to whether you add the new site to the existing
site link or create another site link entirely is dependant, again, upon
whether it truly reflects your connectivity. If all sites are directly
connected to each other, placing them in a single site link is suitable
since it indicates to the DCs that they have a direct, unrestricted path
to any other DC of their choosing. If the sites are connected in a
linear fashion meaning -
(siteA) --> (siteB) --> (siteC)
... then placing all sites in a single link is not optimal since it is,
network wise, more efficient for DCs in siteC to replicate with DCs in
siteB who will in turn propagate the directory changes to DCs in siteA
(the opposite is obviously also true).
Site link bridges are necessary only when some physical or logical
reason prevents packets originating in, for example, siteC from reaching
siteA. In scenarios such as these, replication would obviously fail
between 2 DCs if one of them was in siteA and the other in siteC. To
prevent these unnecessary failures you would tell Active Directory
(specifically the KCC/ISTG componentry) that DCs can only replicate with
other DCs in directly adjacent sites ... this is achieved by deselecting
"Bridge all site links" within Sites and Services. Once this change has
been made, site link bridges become worthwhile (but only in situations
larger than your own) as they allow the Enterprise Admin. to define
pockets of the network that do permit traffic from non-adjacent sites.
--
Dean Wells [MVP / Directory Services]
MSEtechnology
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R e m o v e t h e m a s k t o s e n d e m a i l
Chris said:
Made a lot of sense after I thought about it.....
Along the same lines, as I add new physical locations and sites for
domain controllers I will add site links, correct? I know that the
site links are for representing sites connected by WAN links. I'm
thinking that adding additional sites to a current link wouldn't be a
good idea. Also, at what point would you create a site link bridge?
Dean Wells said:
Member servers/workstations cannot and do not need to be placed in
sites manually. Their site is calculated by the DCs that
authenticate them.
Proactively creating the site and relevant subnet(s) and adding it
to a site-link will cause no harm. Note that it will trigger a
couple of other behaviors on one or more (depending on your existing
configuration) of the other DCs in that they will register DNS
records for that site ... they will deregister them once the
proposed DC you mentioned is manually placed within the site using
AD Sites and Services (or equiv.).
--
Dean Wells [MVP / Directory Services]
MSEtechnology
[[ Please respond to the Newsgroup only regarding posts ]]
R e m o v e t h e m a s k t o s e n d e m a i l
Chris Hall wrote:
Good morning,
We have two locations running win2000 DCs and have recently added
two member servers to our network in a third location. We don't
have a DC installed at this third location, but will be doing so in
the near future. Is there any reason I SHOULDN'T create the
site/subnet structure and move the members servers in?
