Yup, changing it to -lpcap made it compile on my 64 bit CentOS box too.. Sampsa On 9 Apr 2012, at 09:04, Oleg Safiullin wrote: On 04/09/2012 12:33 PM, hvlems at zonnet.nl wrote: Dave, I figured that out too. My system doesn't have a libpcap.a file! If I know how to build one then all would be fine. To build SimH manually wothout libpcap.a (but with libpcap.so.*) you should edit `makefile' and replace line NETWORK_OPT = -DUSE_NETWORK -isystem /usr/local/include /usr/local/lib/libpcap.a with NETWORK_OPT = -DUSE_NETWORK -isystem /usr/local/include -lpcap and then do mkdir BIN make USE_NETWORK=yes