dns-lookup
The server logs the remote users' host address. The default is to
leave the addresses represented as dotted-decimal (i.e. 129.93.33.1) but
if you want you can configure the server so that it looks those addresses
up to get a symbolic host name (i.e. cse.unl.edu).
I recommend that you set the dns-lookup variable to no
because doing the lookups can cause significant performance degradation
(and you can always look up the addresses you want later) and place unnecessary
load on your name server.
Examples:
dns-lookup=no
dns-lookup=yes
Recommendation:
