Hi,Emil Thank you for your help, the example has been linked successfully as you guided after adding '-lresolv'. $(OBJS) -ldhashclient -lutil ../svc/.libs/libsvc.a -lsfsmisc -lsvc -lsfscrypt -larpc -lasync -lresolv -lgmp Wu Yanjun ¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡wuyanjun at mprc.pku.edu.cn ¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡2005-05-08