Sorry if I post something solved on other thread, but I think I am not. I have read several similar issues but to no avail so far. Basically my connection worked perfectly since I installed from scratch Debian 12, 15 days ago. Worked well, both wired and wifi. Yesterday I installed Mozilla's Firefox instead of Debian's Firefox to improve speed. At the same time, my VPN was having login problems, but it ended logging ok.
Mozilla's Firefox was working ok, but suddenly it stopped. My research so far:
ping works
$ ping 8.8.8.8 PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data. 64 bytes from 8.8.8.8: icmp_seq=1 ttl=116 time=9.87 ms 64 bytes from 8.8.8.8: icmp_seq=2 ttl=116 time=9.60 ms 64 bytes from 8.8.8.8: icmp_seq=3 ttl=116 time=9.83 ms 64 bytes from 8.8.8.8: icmp_seq=4 ttl=116 time=9.91 ms ^C --- 8.8.8.8 ping statistics --- 4 packets transmitted, 4 received, 0% packet loss, time 3005ms rtt min/avg/max/mdev = 9.601/9.803/9.910/0.119 ms nmcli is apparently ok for wired connection, including DNS servers. I have dropped wifi by now to focus:
$ nmcli enp0s31f6: conectado to Wired connection 1 "Intel I219-V" ethernet (e1000e), 54:E1:AD:D2:E5:34, hw, mtu 1500 ip4 predeterminado inet4 212.128.174.173/21 inet4 212.128.173.151/21 route4 212.128.168.0/21 metric 100 route4 default via 212.128.168.1 metric 100 route4 169.254.0.0/16 metric 1000 inet6 fe80::56e1:adff:fed2:e534/64 route6 fe80::/64 metric 1024 lo: connected (externally) to lo "lo" loopback (unknown), 00:00:00:00:00:00, sw, mtu 65536 inet4 127.0.0.1/8 inet6 ::1/128 wlp4s0: desconectado "Intel 8265 / 8275" wifi (iwlwifi), E6:46:B6:02:F4:66, hw, mtu 1500 p2p-dev-wlp4s0: desconectado "p2p-dev-wlp4s0" wifi-p2p, hw cdc-wdm0: no disponible "cdc-wdm0" gsm (cdc_mbim), hw DNS configuration: servers: 212.128.130.140 212.128.130.141 domains: ---- (is ok, but not shown for privacy) interface: enp0s31f6 Actually, I can dig a URL via a DNS server:
$ dig @212.128.130.140 linuxconfig.org ; <<>> DiG 9.18.28-1~deb12u2-Debian <<>> @212.128.130.140 linuxconfig.org ; (1 server found) ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 29008 ;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 1 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 1410 ;; QUESTION SECTION: ;linuxconfig.org. IN A ;; ANSWER SECTION: linuxconfig.org. 300 IN A 172.66.40.244 linuxconfig.org. 300 IN A 172.66.43.12 ;; Query time: 16 msec ;; SERVER: 212.128.130.140#53(212.128.130.140) (UDP) ;; WHEN: Wed Sep 18 10:26:44 CEST 2024 ;; MSG SIZE rcvd: 76 But I cannot curl or browse:
$ curl linuxconfig.org curl: (6) Could not resolve host: linuxconfig.org My etc/resolv.conf is empty, just a comment of "#Generated by NetworkManager". Not sure if it is used anymore in Debian 12. Anyways, I cannot edit it even with sudo.
So, that's how far I reached by now. I haven't found anything remarkable in the logs, but maybe I'm not looking ok. Any clues?
Thanks a lot!!!
ping -c3 1.1.1.1andping -c3 google.comandhost google.comwill help show you if it's a DNS issue or a routing issue. (Yes no no → DNS. No no no → Routing)resolv.confshould not be empty - there should be atleast onenameserverentry. Try adding one as a test, likenameserver 8.8.8.8/etc/resolv.conf, how could this be? I cannot edit it with sudo or root, or change the privileges (operation not permitted error). It has-rw-r--r-- 1 root root. That's weird.