AlwaysON Availability Groups - IP address change of secondary replica node
Due to hardware maintenance the IP address of the secondary node will change.


This shouldn't be a problem if the node ip itself is changing. It's only a slight issue if cluster resource ips are changing.


  Is there any actions I should take or anything I should be aware of from a SQL Server, AlwaysON Availability Groups and WSFC perspective?


From the WSFC point of view, assuming that the subnet does not change, there shouldn't be anything needed here.

From SQL Server/AlwaysOn AGs... assuming the subnet does not change:


Double check the AG endpoint to see if it's bound to that specific ip. If it is, that will need changed. If it isn't (wizard generated, etc.) it'll say 'ALL' and that won't need changed.
If SQL Server was setup to listen on specific ip's and ports in configuration manager, this will need changed. If it's set for IPALL, nothing needs done.
If you're using read only routing, double check the read only routing urls and endpoints.
Service broker endpoints (similar to AG endpoint)


From an overall point of view:


Make sure the firewall rules have been edited for the new ip if needed.


This may not be an exhaustive list, but should give you an idea and the most critical areas to look at.