HostnameLookups
HostnameLookups is an Apache HTTP Server directive that controls whether the server performs DNS lookups on client IP addresses to determine hostnames for logging and, to a limited extent, access decisions. When enabled, the server resolves the IP of each client to a hostname and records that hostname in access logs where applicable. When disabled, logs show the client’s IP address directly.
The directive accepts several values. Off (or not set) disables DNS lookups, resulting in IP addresses being
Operational considerations include performance and reliability. DNS lookups add latency and can become a bottleneck on
In practice, HostnameLookups affects log formats that use the remote host field, and its impact should be