When I pass a nonexistent domain name (or, perhaps, more exactly, a malformed domain name), the result, after a noticeable delay, is 11001.
TCC(17.00.69): C:\>echo %@ipaddress[jpsoft]
11001
If I enter a properly formed domain name that does not exist (presumably), I get a different result.
TCC(17.00.69): C:\>echo %@ipaddress[jpsoft.comx.zz]
92.242.140.21
But that is the value that NSLOOKUP returns.
TCC(17.00.69): C:\>nslookup jpsoft.comx.zz
Server: Wireless_Broadband_Router.home
Address: 192.168.1.1
Non-authoritative answer:
Name: jpsoft.comx.zz
Address: 92.242.140.21