On a MacII, trying to make a kernel from recently supped sources, I get: ld ...... vers.o idp_usrreq.o: undefined symbol 'ns_cksum' referenced from text segment ns_error.o: (same thing) ns_error.o: (same thing) spp_usrreq.o (same thing) ***Error Code 1 STOP you have new mail I understand the last line :-) can anyone help me with the first part?? Brad .