DNS Lookup

Log files contain information about user hosts. It may be either a domain name or an IP address. If your web server administrator or your IP disables DNS Lookups for their servers, eWebLog Analyzer can resolve IP addresses itself. If this option is checked in the profile the program will do reverse DNS lookups (the process of translating the numeric IP address that is recorded in the log file into a domain name) before analyzing logs. You must be connected to the Internet during DNS lookup.

The program uses multiple threads to do DNS lookups. The program also caches the lookups. So if the program needs to resolve the IP address that is always in cache it won't need to perform the DNS lookup again.

You can use DNS page of the Options dialog to specify various lookup options:

Number of simultaneous threads
The default number of threads is 100 but if you have the fast Internet connection increasing this number may accelerate the lookup process.

Cache expiration (in days)
After the specified number of days passes since the lookup was performed, the program will try to resolve the IP address again.

DNS lookup timeout (in milliseconds)
Cut-off time that can be set to limit the time for resolving IP Addresses. If the IP Address is not resolved in this period of time, the program will skip the IP Address and proceed to the next IP Address. Note that not all IP Addresses can be resolved. This is dependent on many factors including Internet congestion, the DNS servers in your area, the IP address not having a domain name, etc.

Ask confirmation before analyzing profiles with DNS lookup ON
This option may be useful because you must be connected to Internet while resolving IP addresses so the program will remind you of that.

Clear DNS Cache
Use this button to clear the program's DNS cache.