Dns

Today I spotted some routes from Amazon AWS Cloud services -  AS16509 in Indian tables. AS16509 was originating prefixes while sitting in downstream of Tata-VSNL AS4755 and Reliance AS18101. I almost missed Amazon AWS's announcement on their blog about Indian PoPs for their DNS service - Route53 and CDN service - Cloudfront.

New PoP’s of Amazon in India are at Mumbai and Chennai and I see pretty much consistent BGP announcements to Tata and Reliance from these locations. Prefixes I have seen so far:

And finally ACN i.e “Advanced Computer Networks” exam next. Hopefully less to cram in this one and syllabus is pretty interesting. 

Talking about networks - I am very happy to post this update. Finally F root server’s node in Chennai is back up! 

Though ISC did not updated me about this development but anyways I can always assume they were busy in hitting head with India bureaucratic bodies. :)

If you are following my blog, you might have seen my past blog post about “Broken connectivity of F root server” due to NIXI’s routing policies. When I informed ISC (root server operator for F root) about it, they took down the Indian anycasting instance in order to work on fix. 

And finally academic session over. Done with all vivas and related stuff. Next will be exams likely in June. Time for me to get ready for travel. :)   Anyways an interesting topic for today’s post - Google Public DNS. Lot of us are familier with popular (and free) DNS resolvers 8.8.8.8 and 8.8.4.4. I have covered reason in previous posts on why it tends to fail with Content Delivery networks like Akamai which rely on anycasting at bottom DNS layer and simple unicasting on application servers. Anycasted DNS nodes point to application servers based on various factors like distance, load, cost etc out of interesting algorithms these CDN networks use for load & cost management.   Anyways today’s post focus is not CDN issues with these resolvers but Google Public DNS itself. Are these servers located in India and everywhere else where Google has PoPs?   Let’s do a simple trace to get forward path from Airtel to Google’s 8.8.8.8:

Back in India after amazing APRICOT 2013 at Singapore. It was nice to stay in East Asia for a while and look around. :)

Anyways, issue for today - I have been using Airtel DNS servers from quite sometime since BSNL has crappy DNS while Google gives issues with Akamai while OpenDNS doesn’t has any node in India yet.  

Today I noticed a NXDOMAIN redirection for a non-working domain and later investigated. It seems like Airtel is hijacking on NXDOMAIN queries now.

A quick blog post on a interesting issue coming up due to combined problem of CDN failure on Google Public DNS and bad Akamai performance due to Tata-NTT peering issue.

I was trying Zembra mail since there’s no more free Google Apps edition and one of my friend asked me to basic email on his domain up. It was more or less a straight task by installing Zembra with decent GUI.

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:

It has been an interesting week at village - dry weather, (ultra) dry classes, (boring) external seminars and more of depressing environment but one can always find some hope out of such depressing environment. Overall life here is colourful but one just needs to lookout for colours. :)   One interesting case to report today - F root server has quite bad connectivity in India. Last week a friend asked me for traceroutes to all root servers and here’s what I saw when I did traceroute for F root from BSNL connection:

In last few days, I have been pushing discussion on APNIC & NANOG mailing lists about poor DNS infrastructure in India.

Thought to put a quick blog post on the issue.

So what’s exactly wrong?

To understand what’s wrong, let’s understand how DNS works at core level. DNS relies on a hierarchy model with . (dot) on top which is Root and TLD i.e Top Level Domains below Root, which further  follow 2nd level domains which are popularly domain names we use. So e.g mail.google.com is actually like

Yesterday I called MTS Data Card support but their IVRS system was failing in giving me my balance details. Eventually I decided to email their support and glad to say support email was also easily available on their website.

Today I saw acknowledgement mail in spam. No big deal but I usually dig around genuine mails which go in spam to find exact cause. In this case I found mail was sent to me from  customercare.del@mtsindia.in and the server which relayed this mail was:

DNS Lesson time!

Today, I was just looking into website - ideaisp.net

This site is overall pretty interesting as it’s showing various upstream links of IDEA Cellular ISP backbone. Seems like they are just using Cable & Wireless for most of International bandwidth although IDEA ISP is not functional yet. Anyways, this post is not about their geeky upstream peers & routing tables but how bad one can setup DNS! :)