Dear Friends, I am getting below error message while compiling freeRadius. gcc -o .libs/radeapclient .libs/radeapclient.o libeap/.libs/libfreeradius-eap.so /export/home/lebraaag/PROXY_AAG/RADIUS_STACK/freeradius-server-2.2.0/src/lib/.libs/libfreeradius-radius.so -lnsl -lresolv -lsocket -lposix4 -lpthread -lssl -lcrypto -R/export/home/lebraaag/PROXY_AAG/RADIUS_STACK//lib Undefined first referenced symbol in file *EVP_MD_size* libeap/.libs/libfreeradius-eap.so *BIO_test_flags* libeap/.libs/libfreeradius-eap.so ld: fatal: Symbol referencing errors. No output written to .libs/radeapclient collect2: ld returned 1 exit status I checked the OpenSSL in LD_LIBRARY_PATH variable, it is set /usr/local/ssl/lib/. -- Regards, Srithar Durairaj Alternate Mail I.D: srijeevadurai1@yahoo.co.in Mobile: +919886251852