CertiGuide to Network+  9  Chapter 0101:  TCP/IP       9  V  Name Resolution

LMHOSTS 1 Name Services

The hosts file approach was originally developed back in the days when networks consisted of a few large host computers, whose users normally connected to the computer via “dumb terminals” rather than networked client PC’s of their own. An individual site’s administrator normally had to worry about the configuration of at most a handful of network-connected computers. Therefore, maintaining the hosts file wasn’t that great of an administrative burden. One file had to be updated in a handful of places, every few weeks, as new hosts were added.

However, static mapping’s limitations started to appear as more computers were connected to the network. The hosts file grew at least one line longer every time a system was connected, leading to very large hosts files that were difficult to search and update. Also, the frequency of updates increased. If a new host appeared on the network, odds are some user wanted friendly name access to it almost immediately – and that required the administrator to add it to the hosts file used by that user right then, or to ask the user to have patience until his next scheduled update of hosts (if internal politics permitted that option).

Finally, end users began switching from terminal-based access to network hosts, to using their own desktop PC’s running TCP/IP as network clients. This required hosts files to be distributed to each individual client PC as well as to the organization’s main servers. Distributing these files takes up a lot of network bandwidth, as well as creating a potential problem if some computers’ copies of the file are out of sync with those used on the rest of the network.

LMHOSTS 1 Name Services