Seeing as there are a growing number of people with ethernet interfaces, who wish to have an internet connection and also network shares and file servers etc; why not have a dedicated sticky guide on what software is required and how to set it all up? What is needed is simple and concise explanations where possible, with screen grabs of the various option screens within programs and .inf files. There are bits and pieces of information dotted around the web, although not that much in total.
We have a fair head start with MiNT and a little STinG as wongck has done some excellent guides on his website http://phsw.110mb.com/sw-mintinst.html . For MagiC and STinG there is some info here http://hardware.atari.org/manuals/netsoft.htm although I could not get MagiC to work, well not yet anyway. I will be trying STinG and then MiNT next.
As for other general related software, I will leave that for others to decide upon what is best.
There is some good information contained within the Wiki here http://www.atari-forum.com/wiki/index.php/Sting_Setup
I assume that the reader has some basic understanding on TOS and its derivatives.
First, one needs an 68k Atari: ST, TT or Falcon. It should have at least two megs of ram, the more the better. I presuppose the use of a hard drive. Second, an Ethernec which is an ne2000 compliant networking card with realtek 8019 chipset and an adapter to the Atari romport. The only 68k Atari which can't easily be setup for internet use with this is the ST-Book.
Software needed is the tcp/ip stack Sting, a driver for the networking card (enec.stx, enec3.stx) which can be found in etherne.zip, and the editor Qed or another one that can write 'real' paper writing tabs. Further there should be depackers for Zip and Lzh archives at hand. It is suitable to install wdialog if not using multitasking. Last piece of software is the readily installed Xcontrol.
The Ethernec is placed into the Ataris romport. Then the Atari can be powered on. On the boot drive one makes the folders 'auto' and 'gemsys'. I'd advise to use an additional folder 'data' for the needed archives. Furthermore I suggest to put the applications into a folder 'apps'. The Sting archive has to be unpacked and the data from the unpacked 'auto' folder is moved to 'c:\auto\'. The folders 'sting' and 'cpx' are moved to 'c:\gemsys\'. Now one gets 'enec.stx' (for 68000 Ataris) from the Etherne packet or 'enec3.stx' (for 68030 Ataris) and puts it to 'c:\gemsys\sting\'. Now the files needed to use tcp/ip are at their places.
Next, one starts qed (or the respective editor one prefers) which is used to change some files: First one changes the path in 'c:\auto\sting.inf' to 'c:\gemsys\sting\'. Second one opens the file 'c:\gemsys\sting\route.tab' and writes the line '0.0.0.0[tab]0.0.0.0[tab]EtherNet[tab][ip-address of your router] into it. The tabs have to be tabs, not spaces, else one wonders why nothing is working afterwards. Other lines have to be commented out by setting a '#' as first character in the line. One can set comments after active lines masking them with a '#' as well. You can kill everything as well and just leave the line you inserted. Third in 'c:\gemsys\sting\default.cfg' the line NAMESERVER = [your nameservers' ip] is changed. Now the Xcontrol modul 'Sting Port Setup' is opened and the connection 'Ethernet' is chosen. There an ip address within the routers ip-range has to be specified. 'Subnet mask' is set to 255.255.255.0. The 'active' box has to be enabled. In 'general' choose ne2000 as hardware used. Now save. There will be created a file 'c:\sting.prt'.
After rebooting your system the connection via network should be available.