DNS Resolution with the RESOLVER::name_lookup Command

Hello, thank you for explanation, however I didn't manage to convert RESOLVER::name_lookup in my RESOLV::lookup iRule.

Below what I have:

when HTTP_REQUEST {
set client_IP [IP::client_addr]
set client_hostname [RESOLV::lookup @127.0.0.1 -ptr $client_IP]
HTTP::header replace X-Forwarded-For "$client_IP"
HTTP::header replace X-Forwarded-Host "$client_hostname"
#log local0. "Received XFF Host from $client_hostname"
HTTP::header insert IS_SSL "ssl"
#log
# }
}

Result

info tmm6[28816]: Rule /Common/incas-prod-pool_based_on_client_dns <HTTP_REQUEST>: Received XFF Host from - 10.8.4.42%5

Could you help me please? I upgraded from 14.1.2.8 to 15.1.5 and this irule doesn't work anymore, even if RESOLVER::name_lookup should be still supported with 15.x and 16.x.

Thanks

Regards.