If you prefer to manually edit your configuration files, use the following syntax for this option:

dns on
dns off
dns fast

If set to on, the DNS Resolution (IPs->Names) ^(dns) option indicates that wusage should attempt to look up the host names of sites for which the access log contains only IP addresses.

This is important: if your log already contains full host names for most sites, the DNS Resolution (IPs->Names) ^(dns) option is not recommended. It is not likely that wusage will succeed in looking up the names of sites that your web server could not determine for itself, and a great deal of time will be wasted in the attempt.

If your log does not contain host names, then you may wish to turn on the dns option. Be aware that DNS (Domain Name Service) resolution is a slow operation which requires your computer to contact many other machines on the Internet. Unix versions Wusage 7.0 and above will look up several addresses at one time. However, DNS is still inherently a slow operation.

For much faster results, set dns to fast. This will give you full host names in your reports. However, it does not provide enough information for the Chart Top Domains ^(domains) report or the Ignored Sites ^{(ignoresites)} option to work properly. If you wish to use those features and your log does not already contain host names, you will need to set DNS to on.

If you set the DNS Resolution (IPs->Names) ^(dns) option to on, you will want to set up wusage to run automatically once a night, or once a week, using Unix cron or the Windows NT at command. Wusage is a fast program, but DNS is a slow operation, and it holds up the program considerably. See also the Cache DNS Results for This Many Days ^{(dnscachedays)} option, which controls the reuse of DNS information from one run of Wusage to another, and the Fake DNS ^(fakedns) option, useful within company Intranets. Unix users should also examine the Maximum time in seconds for each DNS lookup ^{(dnslookupseconds)} option.