opendns

Last month I noticed quite high latency with Cisco’s OpenDNS from my home fibre connection. The provider at home is IAXN (AS134316) which is peering with content folks in Delhi besides transit from Airtel. ping -c 5 208.67.222.222 PING 208.67.222.222 (208.67.222.222) 56(84) bytes of data. 64 bytes from 208.67.222.222: icmp_seq=1 ttl=51 time=103 ms 64 bytes from 208.67.222.222: icmp_seq=2 ttl=51 time=103 ms 64 bytes from 208.67.222.222: icmp_seq=3 ttl=51 time=103 ms 64 bytes from 208.

Writing this post from my hotel room in Kathmandu. I found that many of the servers appear to be DNS resolvers which is unusual. Have a look at these weird DNS replies: dig @anuragbhatia.com . ns +short a.root-servers.net. b.root-servers.net. c.root-servers.net. d.root-servers.net. e.root-servers.net. f.root-servers.net. g.root-servers.net. h.root-servers.net. i.root-servers.net. j.root-servers.net. k.root-servers.net. l.root-servers.net. m.root-servers.net. dig @google.com . ns +short b.root-servers.net. c.root-servers.net. d.root-servers.net. e.root-servers.net. f.root-servers.net. g.root-servers.net. h.root-servers.net. i.root-servers.net. j.root-servers.net. k.root-servers.net. l.root-servers.net. m.root-servers.net. a.root-servers.net. This seems unusual and is the result of basically port 53 DNS hijack.

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:

Hello everyone! Seems like Tata Communications routing table is changed (call it fixed) to route traffic for openDNS to Singapore. It’s not going to London anymore and I see very good latency from BSNL too (which uses Tata Comm for most of it’s International traffic). Here’s latest routing from BSNL to openDNS: HOST: laptop Loss% Snt Last Avg Best Wrst StDev 1. router2 0.0% 50 2.0 1.7 1.5 2.2 0.2 2.