hosting question

[Boron]

i wanted to try dom with a friend . i myself can host without problem but he seems to be unable to host and so can't connect to me too .
i myself use a router so are there any ports which must be open aside from the one port dominions uses ?

my friend has windows 98 , no router , no firewall .
but he says he is unable to connect to himself when he hosts like written in the manual . he always gets an errormessage . for me myself it works well if i use my router ip .

which ip does he need to use the internet ip or another ? he said he tried both the internet one and the one dominions server said but perhaps he made a fault .

so what should he try is there perhaps a little trick with windows 98 to get it work with dominions ?

surprisingly when i tried to setup the server i could connect to him but he not to himself .
any suggestions ?