What kind of firewall settings we have to do in case we are setting up our Standalone FTP Attachments®?

Standalone installation includes following 3 components - 

• Salesforce.com instance
• FTP Attachments® Application Server (Windows Server with IIS)
• Storage Server (Where actual files will be stored)

You need to make appropriate firewall settings as following,

• Application server should be able to talk to *.salesforce.com on port 443
• Application server should be able to talk to *.enzigma.com, *.ftpattachments.com on port 443
• Application server should be able to talk to Storage server on appropriate port (e.g. for FTP port 21)
• Only port which needs to be open on Application server are 80 and/or 443 (443 is required only if you are using https to access the FTP Attachments®)