Google-Dns

EDNS support by Google's Public DNS

Just was looking around at EDNS support by Google. To find how it supports and how packet looks like I created a test NS records for dnstest.anuragbhatia.com pointing to one of test server (178.238.225.247). I wasn’t running any DNS server on the server. Just ran quick tcpdump.  

At server end:

sudo tcpdump 'port 53 and dst 178.238.225.247' -nn -vvv -w sample.pcap

Then I forcefully triggered DNS queries via Google’s recursor using:**

Akamai CDN and DNS resolution analysis

These days Open DNS resolvers are getting quite popular. With Open DNS resolver I mean resolvers including OpenDNS as well as Google Public DNS.

One of major issues these resolvers suffer is failure of integration with CDN providers like Akamai, Limelight etc. In this post I will analyse sample client site of Akamai - Malaysia Airlines website - http://www.malaysiaairlines.com.  

Looking at OpenDNS, Google Public DNS and my ISP (BSNL’s) DNS resolver for its DNS records: