>Finaly one have to check the parts of the URL for valid signs. This is all what one can do.
>Possible for the IP based one can check for wrong values (386.99.0.1 is not possible)

But 32343.44321 may be ok, because, in the end, it's just one long integer which needs to be there - expressed as four bytes, two words or one long... I think even a hex notation is accepted in some shape.