The scanner automatically performs reverse DNS lookups on an IP address. If the DNS server supplied to the scanner, doesn't have the host name of that IP - there will be no data. If you supply a primary and a back up DNS server, we attempt to contact the primary first. If the primary is up, and it doesn't have the record, we report no host name. If the primary is down, we shift to the secondary.
Are these devices listed on your internal DNS server?
Thank you for your answer.
We are using the scanner appliances in a split configuration and we configured the same DNS server for both the LAN and the WAN interfaces(22.214.171.124). Now I understand the LAN interface should have been configured with the internal DNS server. (I wonder: how are the windows servers hostname being correctly resolved without proper DNS configuration?)
The problem is that we have a wide segmented network. Each segment has an independent DNS server. The same Appliances are being used to scan all those segments. We are using different LAN IPs for different VLANs. Those are configured on the VLAN tab of the scanner appliances edit Window. Is there anyway we can configure Qualys to change the DNS server IP address as it changes the LAN Ip address and the VLAN tagging (If not, I'd like to make this a "feature request")?