On non-fully IP routed networks, disable automatic site links, implement a site link bridge
A site link is a set of sites which communicate at the same cost, and can be automatically configured to route in a redundant path between sites within a site-link
In a fully routed network, you do not need site link bridges unless you wanted to specifically control the flow of replication changes.
Controls which sites are connected and at what cost, but does not directly control which servers replicate with one another, this would be the role of a Preferred Bridgehead Server
Best Practice to create site links from corporate to branches, little benefit in having a tiered site line corp->branch->branch
You cannot create site-links between networks which are not IP routed
Site link bridging is used when an IP network is not fully routed; or if replication is not converging properly (used when site’s are 2+ hops away)
Site links are for same domain only, and are between IP-routable networks unless you use a ip bridge to connect two non-routable network in the same domain;
If two non-routable domains are separated by a site in a different domain, you will need to have a DC setup in that site or you will need a routable network
IP Replication for single domain sites; SMTP not available
