The latest version of the network code can be obtained by anonymous FTP from various sites. The official FTP site for Net-3 is sunacm.swan.ac.uk, mirrored by sunsite.unc.edu below system/Network/sunacm. The latest Net-2e patch kit and binaries are available from ftp.aris.com. Matthias Urlichs' BSD-derived networking code can be gotten from ftp.ira.uka.de in /pub/system/linux/netbsd.
The latest kernels can be found on nic.funet.fi in /pub/OS/Linux/PEOPLE/Linus; sunsite and tsx-11.mit.edu mirror this directory.