Sharepoint 2013 Farm configuration

Hi,

I have a sharepoint 2013 farm which consists of

4 web fornt end

1 Application server

1 databaseserver.

I have a intranet site say for eg :- http://mycompany.intranet.

What I want is when the user is on the company network and he tries to access the site he should be redirected to WFE1 and WFE.

If the user is trying to access the site over the internet he should be redirected to WFE3 and WFE4.

How can this be achieved.

Thanks