Errors from compiling examples for libpq++

Hi,

I have tried to compile examples in libpq++. I got the following errors:

postgres(at)vaca1>make all -f Makefile
g++ -Wno-error -Wno-unused -Wl,-Bdynamic
-I/U07/postgres/usr/src/pgsql/postgresql-6.5/include -o testlibpq0
testlibpq0.cc -L/U07/postgres/usr/src/pgsql/postgresql-6.5/lib -lpq++
Undefined first referenced
symbol in file
socket
/U07/postgres/usr/src/pgsql/postgresql-6.5/lib/libpq++.so
recv
/U07/postgres/usr/src/pgsql/postgresql-6.5/lib/libpq++.so
getprotobyname
/U07/postgres/usr/src/pgsql/postgresql-6.5/lib/libpq++.so
gethostbyname
/U07/postgres/usr/src/pgsql/postgresql-6.5/lib/libpq++.so
send
/U07/postgres/usr/src/pgsql/postgresql-6.5/lib/libpq++.so
setsockopt
/U07/postgres/usr/src/pgsql/postgresql-6.5/lib/libpq++.so
getsockname
/U07/postgres/usr/src/pgsql/postgresql-6.5/lib/libpq++.so
connect
/U07/postgres/usr/src/pgsql/postgresql-6.5/lib/libpq++.so
ld: fatal: Symbol referencing errors. No output written to testlibpq0
collect2: ld returned 1 exit status
make: *** [testlibpq0] Error 1

Could anyone help me and let me know whether there is something wrong with
the initial setup and how can I avoid the errors? I am using g++ (gcc
2.8.1) on Sun solaries 2.6.

Thank you for help.

Jim