Hello! Thanks for you help! All right, I was able to compile freeradius with firebird support! =) my inexperience, some later I noticed that configure --help tells me next params: --with-experimental-modules, and also I viewed the file "stable" in src.../drivers directory, and saw that firebird is not stable. Then I'am run configure with next params: ./configure --prefix=/usr \ --exec-prefix=/usr \ --mandir=/usr/share/man \ --sysconfdir=/etc \ --libdir=/usr/lib/freeradius \ --datadir=/usr/share \ --localstatedir=/var \ --with-raddbdir=/etc/freeradius \ --with-logdir=/var/log/freeradius \ --enable-ltdl-install=no --enable-strict-dependencies \ --with-large-files --with-udpfromto --with-edir \ --enable-developer \ --config-cache \ --without-rlm_eap_tnc \ --without-rlm_sql_postgresql \ --without-rlm_eap_ikev2 \ --without-rlm_sql_oracle \ --without-rlm_sql_unixodbc \ --with-system-libtool \ --with-system-libltdl \ --with-experimental-modules \ --without-rlm_opendirectory \ --without-rlm_redis \ --without-rlm_rediswho \ --without-rlm_ruby \ --without-rlm_sql_sqlite \ --without-rlm_sql_db2 and then make and checkinstall make install as a result I got the module freeradius-XYZ.deb, which was successfully installed in the system. Yes, I expected that I must be got separate module, as to freeradius-firebird.deb, thanks you for you explaining, that my expectations are wrong. =) And question about why we are using firebird database. The reason is very simple, out billing software begun develops long ago, and for historical reasons used firebird database engine. This software was developed inside the company, and modernization of it is a complex process in which we do not need, except that we can't use freeradius, unfortunately, in production. May be only after full testing, may be. It is a pity that the module is still experimental, eh. Thanks for your answers!