found a "problem" in MorphOS 2.5 (There is not this problem in MorphOS 2.4) with TCP/IP stack, service DNS.
For exemple, if I use my internal DNS server, and then I decide to change it with one or two external DNS for exemple, I select "save" in network preferences, but this has no results ... no way to ping/resolve an address name ... I must reboot MorphOS 2.5, then all works ok.