Hi all, I'm reading about setting up Active Directory Sites and need a little help visualizing something. I understand that to schedule replication between 2 sites, we want to create a site link that contains the two sites. Also we will want to assign a cost to these links. Now lets say I have Site A and Site B connected via a T1, with a dial-up connection for backup. I would want to create two site links right? One for the T1 and one for the dial-up connection and assign the dial-up connection a higher cost right? All good so far? Now, I get confused here. Lets say the primary T1 link is down and we are using our dial-up backup connection. How does Active Directory know to use the link we created for the dial-up connection? Probably a dumb question, but I have seen this scenario presented when trying to explain sites and site links and haven't seen anyone explain exactly how Active Directory know what site link to use. Thanks for any help!

Hello in2jars, Generally it's up to the Gateway router that joins the two inter-connected networks to switch over to a backup link when the primary link fails or to balance via cost. There are many router/firewalls that can perform this function, Sonicwall, Cisco, Checkpoint to name some. Usually when you have a scenario like this, you have a VPN that joins both sites. The main link may be a T-1 with a backup DSL, Wireless or Dial-Up. The gateway router will be in charge of redundancy. CheersMiguel Fra / Falcon ITS Computer & Network Support, Miami, FL Visit our Knowledgebase Sharepoint Site

Thanks Falcon, I understand the gateway routers at each site would be responsible for the actual failing over to a backup link. But still, if I had two site links defined in AD, say one for the T1 that is set to replicate every hour vs. a site link for the backup connection that is set to replicate every say 4 hours, how does AD know it is now time to use the other link with a longer replication time? Thanks again!

Hello, As far as my knowledge, the site links concerned with server to server communications. They are not aware of, or have a say in how the packets arrive from point a to point b. That is the job of the gateway router. Miguel Miguel Fra / Falcon ITS Computer & Network Support, Miami, FL Visit our Knowledgebase Sharepoint Site

Hello again in2jars, Check out these articles: http://technet.microsoft.com/en-us/library/dd277429.aspx http://technet.microsoft.com/en-us/library/cc728261(WS.10).aspx CheersMiguel Fra / Falcon ITS Computer & Network Support, Miami, FL Visit our Knowledgebase Sharepoint Site