cannot access github.com

I cannot nslookup github: nslookup github 8.8.8.8 ;; connection timed out; no servers could be reached nslookup github.com ;; connection timed out; no servers could be reached nb: default ns server = gw = router 4g = 192.168.0.1 (a cache dns server I guess). I am on a 192.168.0.0/24, my ip = 192.168.0.130, bcast = 192.168.0.255, ip given by router via dhcp. my nslookup seems to be working: nslookup google.com Server: 8.8.8.8 Address: 8.8.8.8#53 Non-authoritative answer: Name: google.com Address: 142.250.187.206 Name: google.com Address: 2a00:1450:4009:81f::200e I can tlslookup github.com tlslookup github.com 140.82.113.4 nb: I dont know why resolution works with this tool and not with nslookup. I tried to grab infos regarding tlslookup over google but nothing. I check with dig (just in case my nslookup does not work fine). Unfortunately the pb remains with this tool. dig github.com ; > DiG 9.16.27-Debian > github.com ;; global options: +cmd ;; connection timed out; no servers could be reached dig @8.8.8.8 github.com ; > DiG 9.16.27-Debian > @8.8.8.8 github.com ; (1 server found) ;; global options: +cmd ;; connection timed out; no servers could be reached Obviously all commands relying on name resolution wont work, but for the sake of the post, I tried some of them: ping $(tlslookup github.com) PING 140.82.114.3 (140.82.114.3) 56(84) bytes of data. 64 bytes from 140.82.114.3: icmp_seq=1 ttl=50 time=259 ms 64 bytes from 140.82.114.3: icmp_seq=2 ttl=50 time=317 ms 64 bytes from 140.82.114.3: icmp_seq=3 ttl=50 time=238 ms ^C --- 140.82.114.3 ping statistics --- 3 packets transmitted, 3 received, 0% packet loss, time 2002ms rtt min/avg/max/mdev = 237.514/271.189/316.968/33.546 ms but ping github.com ping: github.com: Temporary failure in name resolution openssl s_client -connect github.com:443 140311527400768:error:2008F002:BIO routines:BIO_lookup_ex:system lib:../crypto/bio/b_addr.c:730:Temporary failure in name resolution connect:errno=11 wget github.com --2022-04-28 09:52:02-- http://github.com/ Resolving github.com (github.com)... failed: Temporary failure in name resolution. wget: unable to resolve host address ‘github.com’ I tried to wget website ip address: wget 140.82.113.3 --2022-04-28 10:01:13-- http://140.82.113.3/ Connecting to 140.82.113.3:80... connected. HTTP request sent, awaiting response... 301 Moved Permanently Location: https://140.82.113.3/ [following] --2022-04-28 10:01:13-- https://140.82.113.3/ Connecting to 140.82.113.3:443... connected. The certificate's owner does not match hostname ‘140.82.113.3’ if I browse the ip address, I have got a warning message saying the cert is wrong, if I try to pass it over (accept risk), there is no way to access website. nothing blocking in my hosts file: cat /etc/hosts 127.0.0.1 localhost 127.0.1.1 zavata.circus.net zavata # The following lines are desirable for IPv6 capable hosts ::1 localhost ip6-localhost ip6-loopback ff02::1 ip6-allnodes ff02::2 ip6-allrouters Everything look fine in my routing table (192.168.0.1 beeing my default gw, a 4g router) route -n Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 0.0.0.0 192.168.0.1 0.0.0.0 UG 600 0 0 wlp1s0 169.254.0.0 0.0.0.0 255.255.0.0 U 1000 0 0 wlp1s0 192.168.0.0 0.0.0.0 255.255.255.0 U 600 0 0 wlp1s0 Many thanx folks !!