DNS filter is not working

[jhansibalu (jhansi)]

Hi here I am trying to resolve the hostname to host ipaddress

Here is my dns configuration in filter block

mutate {
rename => {"host" => "[host][hostname]"}
add_field => {"[host][ipaddress]" => "%{[host][hostname]}" }
}
dns {
resolve => [ "[host][ipaddress]" ]
action => "replace"
}

            }

I want is to replace all Host names with a IP with the DNS Filter.
I am not getting any error but it doesn't resolve all hosts.
How to fix this issue.

Thanks

[warkolm (Mark Walkom)]

What sorts of hosts is it not resolving?