SWITCH Security-Blog

SWITCH-CERT IT-Security Blog


Top 1000 .ch Domain Names

UPDATE 19.02.2019:

From February 2019 on there will be a few small changes. A co-worker, Antoine, has discovered a flaw in the current measurement of the top 1000 .ch domain names which has been removed by now. Since we only counted the number of distinct IP addresses per domain for both IP versions, using IPv6 one can easily send queries from a whole /64 range which results in approximately 1.8*10^19 different addresses. Being a private customer of the Swiss ISP Init7 even gives you an entire /48 range. Like that you can easily push a domain name to the top! In order to prevent this from happening we will now count the distinct number of ASes per domain.

Additionally, we will provide 2 lists from now on. One that contains a ranking based on ALL queries, i.e. including queries that have returned NXDOMAIN, and one whithout those NXDOMAIN queries. Previously, we just provided the former. Continue reading