(in this case of router / DNS lookup) The last component / suffix of a router address is the top-level domain e.g. '.com', '.net', '.gov', '.uk', etc.

Related content:

Content Type: Report page


Technical data >> Domains

Use the Domains report to identify which domains are the most popular for accessing your site. Generally speaking, these are country TLDs (top-level-domains) although the list may also be headed off by...
Content Type: Report page


Technical data >> Routers

Use the Routers report to identify which routers are the most popular for accessing your site. 
Using the calendar, you can select any date range required. The date range is displayed in the Options...