dnsutils

[60] % nix-shell -p bind.dnsutils --run "dig releases.nixos.org"
warning: Nix search path entry '/nix/var/nix/profiles/per-user/root/channels/n
ixpkgs' does not exist, ignoring                                             

; <<>> DiG 9.12.3 <<>> releases.nixos.org
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 38761
;; flags: qr rd ra ad; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;releases.nixos.org.            IN      A

;; ANSWER SECTION:
releases.nixos.org.     2296    IN      A       54.217.220.47

;; Query time: 1 msec
;; SERVER: 192.168.15.1#53(192.168.15.1)
;; WHEN: qui dez 20 17:59:40 -02 2018
;; MSG SIZE  rcvd: 63

log

[60] % curl -LI4 https://nixos.org/channels/nixpkgs-unstable
HTTP/1.1 302 Found
Date: Thu, 20 Dec 2018 19:50:29 GMT
Server: Apache/2.4.33 (Unix) OpenSSL/1.0.2o
Strict-Transport-Security: max-age=15552000
Location: https://releases.nixos.org/nixpkgs/nixpkgs-19.03pre161900.61c3169a0e
1                                                                            
Content-Type: text/html; charset=iso-8859-1

curl: (60) SSL: no alternative certificate subject name matches target host na
me 'releases.nixos.org'                                                      
More details here: https://curl.haxx.se/docs/sslcerts.html

curl failed to verify the legitimacy of the server and therefore could not
establish a secure connection to it. To learn more about this situation and
how to fix it, please visit the web page mentioned above.