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I will use the CCISD as an example. On the CCISD website there is a link to PowerSchool which points to http://powerschool.copperisd.org. This is a CNAME to webservices.remc1.net. Inside webservices there is a virtual host that does a redirect to pscopperisd.remc1.net. pscopperisd will differ from the inside and the outside. On the inside DNS this is CNAMEed to the current PowerSchool server (at time of writing that is ps2copperisd.remc1.net). On the outside that is an A record to the one public IP that is held by the PowerSchool server for the CopperISD. I have also inserted CNAMES for all the ps1, ps2, ectetc. on the outside to point towards it's A record.
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