I have a list of IP's to exclude within a given report suite. Does anybody know if historical data within the report suite is excluded or only data going forward from the date/time of the exclusion?
Here few ways to exclude the IP Addresses : Adobe Analytics Help | Methods to exclude data in Analytics
It is not historic and will be excluded only from the date, the rules are applied.
Also worth considering is creating exclude segment(s) ... if your IP's exhibit a specific behavior ie. correspond to a domain not applicable to other IPs (you do not want to filter). this would be historical.
You can also use Report Time Processing to create a virtual report suite that "reprocesses" your data without the IP addresses in question.