Chromium based browsers & DNS

While this is not something new, it perhaps has more significance because of the ever increasing market share of more than 60% of Chromium based browsers.

Chromium based browsers have a very uncanny method to check if the web browser is sitting behind a captive portal. And if you’re running a recursive resolver in your network with a large user base running Chromium based browsers (Google Chrome, Brave etc), it might even startle you if you observe the recursive resolver logs.

Here is a snippet from my unbound resolver as soon as I start Google Chrome on the machine(,

Jun  3 11:16:31 root unbound: [1283:0] info: pwpsfrn. A IN
Jun  3 11:16:31 root unbound: [1283:0] info: yeytluindg. A IN
Jun  3 11:16:31 root unbound: [1283:0] info: zkgtcrxrpfjcjxr. A IN

A research project at USC What’s In A Name? goes into some detail with the classification.

Here is the summary of the study,

Though the root server system handles this application-specific load sufficiently, it is clear that Chrome’s trick of using randomly generated names to discover whether it’s behind a captive portal contributes significantly to the traffic received at the root zone.

What’s in a name? – Wes Hardaker

Educational & Research Institutions in India having their own ASN

A few months ago, Pranesh had asked if there are any universities in India that have their own ASN.

I think the answer warrants a few more details.

AS132785Shiv Nadar University
AS137282KIIT University
AS133552B.M.S College Of Engineering
AS38872Indian School of Business
AS137617Indian Institute Of Management, Ahmedabad
AS136304Institute Of Physics, Bhubaneswar
AS138231Indian Institute Of Information Technology, Allahabad
AS137956Indian Institute of Technology, Ropar
AS134901Indian Institute Of Science Education And Research
AS132749Indraprastha Institute of Information Technology, Delhi
AS2697ERNET (Education and Research Network) India (Also peers with AS55824 – NKN Core Network)

ASN’s part of NKN(National Knowledge Network) Core Network (AS55824)

AS59163GLA University
AS138155Jawaharlal Nehru University
AS55566Inter University Centre for Astronomy and Astrophysics
AS134023Aligarh Muslim University
AS132995South Asian University
AS58758Tata Institute of Fundamental Research (Also has AS4755 as IPv4 peer)
AS134934Institute For Stem Cell Biology And Regenerative Medicine (Also has AS45820 AS IPv4 peer)
AS134322Tata Institute of Fundamental Research (Also has AS9498 as IPv4 peer)
AS132524Tata Institute of Fundamental Research (Also has AS18101 as IPv4 peer)
AS23770Tata Institute of Fundamental Research (Also has AS45820 as IPv6 peer)
AS137136Indian Agricultural Statistics Research Institute
AS136005Raman Research Institute
AS135730Datta Meghe Institute Of Medical Sciences
AS133723Institute for Plasma Research
AS133313Saha Institute of Nuclear Physics
AS133273Tata Institute of Social Sciences
AS133002Indian Institute of Tropical Meteorology
AS132780Indian Institute of Technology, Delhi
AS131226Indian Institute Of Technology, Roorkee

While the data on NKN’s website mentions about 1622 connected institutions, apart from the list above, the majority of them do not have an ASN.

I will visit this post every few months and update the data.