logging - have IIS logs get client name -

i'm attempting use custom fields features created in iis 8.5 log client name (or instead of) client ip. when parsing through logs, it's important if username not supplied page have way identify user. trying lookup these ips time consuming, , makes runtime programs doing incredibly slow. if know how configure field, or can point me in right direction, appreciate it.

you run powershell command:

set-webconfigurationproperty -pspath 'machine/webroot/apphost' -location 'default web site' -filter "system.webserver/security/ipsecurity" -name "enablereversedns" -value "true" 

replace default web site site's name, need iis management scripts , tools installed.

but really, shouldn't.

as write yourself:

trying lookup these ips time consuming,

iis not after request has been answered, before processes , therefore makes whole web server slower before.

when changing in gui, get: