To compile pcapsipdump under solaris10, you need:
- gcc3
- libpcap

both can be installed from blastwave (http://www.blastwave.org/howto.html) like this:
# pkgadd -d http://www.blastwave.org/pkg_get.pkg
# vi /opt/csw/etc/pkg-get.conf (optional)
# /opt/csw/bin/pkg-get -i wget
# /opt/csw/bin/pkg-get -i gcc3g++
# /opt/csw/bin/pkg-get -i libpcap

When pre-requirements are met, just untar source and issue:
# make CC=/opt/csw/gcc3/bin/gcc LDFLAGS='-lnsl -lsocket'
# make install