Some other things I found out, when trying to compile Socket6 (whether using CPAN or manually running the module make and compile) be sure that the compiler that was used to install Perl is on the path. If the make cannot find the same compiler the make will choke, this happened to me on a couple of Solaris boxes and on AIX. To find out what compiler was used for Perl run:

perl -V

Yes, that is an upper case V, you should see something like:

Compiler: cc='cc', ccflags ='-D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -xarch=v8 -D_TS_ERRNO',

If that does not match what the Makefile has there will be problems, the solution that was necessary for me on Solaris and AIX is that we needed to adjust the paths in my shell to avoid use of gcc which was not used for the perl compiles but was getting picked up in my environment. In addition, on AIX it will sometimes be configured to have something like cc_r as the base compiler, which is a link to xlc, and the way they are called can be hairy. There is more information on this here - Embedded Perl on AIX

Sorry to mix stuff here, but I was working on multiple platforms and I ended up wanting to keep this all together.