irule to block file types from extenal client IP

Can you try this?

when HTTP_REQUEST {
if { [IP::addr [IP::client_addr] equals x.x.x.166] and [string tolower [HTTP::host]] contains "devintdocs" } {
switch -glob [URI::decode [string tolower [HTTP::path]]] {
"*.xls" -
"*.xlsx" -
"*.doc" -
"*.docx" -
"*.ppt" -
"*.pptx" }{
HTTP::respond 200 content {
Apology Page
We are sorry, but the document you are attempting to access is restricted by Corporate Policy. 
If you feel you have reached this page in error, please contact your supervisor.
}
}
} else {
switch [HTTP::host] {
"devintportal" { pool sharepoint_devint_Pool1 }
"devintmy" { pool sharepoint_devint_Pool2 }
"devintdocs" { pool sharepoint_devint_Pool3 }
"devintteams" { pool sharepoint_devint_Pool4 }
"partners" { pool sharepoint_devint_Pool5 }
}
}
}

You might also want to add a check to see if the host is null or an IP address to the first check. Also make sure to add a OneConnect profile to the virtual server as you're selecting a pool in some cases but not all.

Aaron