Not any more, they’re not! As long as you take Ashley McGlone’s advice in Freaky neat Active Directory site links with PowerShell:
Today's post will help you clean up site link descriptions and give you some nice reporting capability. For a quick overview of the terminology you can read the landmark TechNet article How Replication Works. To make a long story short admins create sites and then link them together with site links. Like most things in life change happens, and we don't go back to clean up afterwards. I commonly find orphaned site links, mondo links with too many sites, and site link descriptions that haven't been updated to reflect their member sites.
If you’ve washed your hands enough today and would rather scrub site links (like me!) then Ashley has some link-hygiene goodness:
In the script file attached at the end of the post I have included all of the scripts above plus some bonus content. There is a site report script that will give you some schweet stats on your AD sites. Use it to find those sites that are not in a site link, missing subnets, or do not have a DC.
The scripts are for PowerShell V2. And (bonus!) there’s a picture of Adrian Monk, if you like that when scripting. I do. Enjoy!