Weird, switch only seems to support legacy ip.
whois.nic.ch has address 130.59.31.241 whois.nic.ch has IPv6 address 2001:620:0:ff::b
$ whois -h 130.59.31.241 imp.ch This information is subject to an Acceptable Use Policy. See https://www.nic.ch/terms/aup/
Domain name: imp.ch [...]
$ whois -h 2001:620:0:ff::b imp.ch Requests of this client are not permitted. Please use https://www.nic.ch/whois/ for queries.
Mit freundlichen Grüssen
-Benoît Panizzon-