How to show DNS names in widgets
Apex can resolve the DNS names of IP addresses shown in dashboard widgets. For that to happen, you must configure IP address fields in your widgets after specifying one or two DNS servers in the general settings.
Prerequisite(s):  
You must specify DNS servers before DNS resolution can take place.
You must be editing a widget that has, or you plan to add it, at least one IP address key field.
 
To show DNS names in dashboard results, you will edit the IP address key fields in your widget or widgets to show the IP address as a DNS name. Then, each time the widget appears in a dashboard, the dashboard widget displays a DNS name, IP address, or both, depending on its configuration.
Tip! If an IP address is not resolvable to a DNS name, it continues to appear as an IP address in your dashboards.
1. In the web interface, click Configuration > Widget Library.
2. Select a widget from the leftmost pane by clicking it.
The widget is now editable.
3. Click Edit Fields from the top row of tabs.
4. Under Field List, click a key field that bears an IP address.
Apex widget DNS resolutionApex widget DNS resolution
By clicking IP Address - Pair, we see that DNS resolution settings are available in the standard Field Properties area.
5. Change Display As to DNS only or IP and DNS.
6. Click the accept icon .
 
Resolved DNS names now appear where those widget fields are used in dashboards as long as the IPs are resolvable by your configured DNS server(s).