Hank Arnold said:
Herb,
As a general rule, is it a bad idea to have scavenging turned on? Or is you
comment aimed strictly at the issue of a branch DC?
There is no trivial answer -- sorry.
The key is that you MUST NOT allow AD-DNS DCs to be separated long
enough to scavenge each other.
Such separation is not likely on a LAN, so this is mainly a WAN issue
(unless the DC is down but then a local DC is usually easier to troubleshoot
and fix even with AD authentication problems.)
So, you must especially watch having scavenging turned on, short periods,
timeouts, and WAN lines down for longer than the scavenging timeouts.
So those people thinking to set scavenging to something like "1-day" get
themselves in trouble sooner or later, and even those thinking to set it
to "1-week" are NOT safe.
(I am not talking about just Scavenging Period here though, but the
composite:
NoRefreshInterval + RefreshInterval and Scavenging Period.)
And all this can interact with the DC SiteLink replication frequency and
schedule.