Thanks all for the tips.

I'm not sure why Net::Pcap installation would try to use the Solaris cc and not gcc. We have gcc installed on our system, and I have succesfully installed other Perl modules in the past (which used gcc).

Maybe there is something about Net::Pcap's use of $Config in the Makefile.PL that does not work on Solaris. I noticed that this module has not been tested for awhile on Solaris.

Since all I want to do is have my program write a pcap file, I suppose another option is to just write a C program that does this, and add a system() call to the C program from my Perl script. But it would be much nicer if I could do the whole thing in Perl...