I am facing the same problem with the same hardware and I have tested that this ethernet controller works under FreeBSD with the fxp(4) driver, which is consistent with the web page referred to: ... Adapters supported by the fxp(4) driver include: ... * Many on-board network interfaces on Intel motherboards ... Hope this helps to make Debian/kfreebsd installer work too!
The driver is disabled as it requires non-free firmware. See #594940: The following C files contain firmware images in binary-equivalent form but are not obviously accompanied by the corresponding source code: sys/dev/fxp/rcvbundl.h - binaries are packaged in firmware-linux-nonfree as /lib/firmware/e100/* Petr