fixed how to

howto.md

@@ -9,6 +9,50 @@ npm init
 
 how to duplicate DNS crash:
 
+```
+cd ~/dns_test
+```
 
-How to print out hex and binary values of the message?
+```
+node listen.js
+```
 
+```
+dig @224.0.0.251 -p 5353 -t PTR _cloud._tcp.local
+```
+
+The output is then:
+
+```
+START DNS PACKET
+/home/daplie/dns_test/node_modules/dns-js/lib/bufferconsumer.js:52
+      throw new Error('Buffer overflow')
+      ^
+
+Error: Buffer overflow
+    at BufferConsumer.slice (/home/daplie/dns_test/node_modules/dns-js/lib/bufferconsumer.js:52:13)
+  s  at Function.DNSRecord.parse (/home/daplie/dns_test/node_modules/dns-js/lib/dnsrecord.js:237:46)
+    at /home/daplie/dns_test/node_modules/dns-js/lib/dnspacket.js:164:30
+    at Array.forEach (native)
+    at Function.DNSPacket.parse (/home/daplie/dns_test/node_modules/dns-js/lib/dnspacket.js:159:17)
+    at /home/daplie/dns_test/cloud-respond.js:86:31
+    at Array.forEach (native)
+    at /home/daplie/dns_test/cloud-respond.js:11:21
+    at Array.forEach (native)
+    at Object.module.exports.respond (/home/daplie/dns_test/cloud-respond.js:10:11)
+
+```
+
+
+
+
+How to print out hex values of the DNS message?
+
+```javascript
+socket.on('message', function (message, rinfo) {
+  console.log('Received %d bytes from %s:%d\n',
+    message.length, rinfo.address, rinfo.port);
+  //console.log(msg.toString('utf8'));
+
+  console.log(message.toString('hex'));
+```