An update - I had success using compiling using 'cpp' instead of 'gcc'

cpp is not a compiler. it will only resolve your #include #define etc but the output is still C.

I now receive less error output, but there's still an error:

Your crosscompiler setup is seriously broken! It apparently misses critical include file contents, the first error about IPPORT_ROUTESERVER was also caused by that.

Maybe you missed some step in setting it up, I remember from the past where I tried this for my Dreambox that it is quite an involved procedure.

Rob