when HTTP_REQUEST {
if { ([string tolower [HTTP::host]] eq "externalsitea.company.com") && ([HTTP::path] eq "/" ) }{
HTTP::header replace Host "internalsitexyz"
HTTP::path "/aba/blabla/12345"
} else {
return
}
}
Client talks to 'externalsitea.company.com' and meanwhile, behind the scenes, F5 forwards such requests to your Pool Member as 'GET internalsitexyz/aba/blabla/12345'.
That solution only masquerades headers. If you need to modify response payload (i.e. some HTML links), you will need to use a stream profile https://devcentral.f5.com/questions/rewrite-body-of-web-site