"xp host" with "shared dsl dail-up"

hi
i've a "xp host" with "shared dsl dail-up (ISC)" for internet connection. my guest OS is the same XP pro. i checked all DHCP assigned IP's. i can ping, control the ISC from the guest (connect/disconnect). but a IE doesn't see the web "The page cannot be displayed".

any hint?

many thanks
Ueli