Ethernet interface is up but there is no network access

I have an ethernet cable connected to my home server but I have no internet connection despite the interface having status UP. I cannot even ping the router (at 192.168.10.1). When I plug the same cable into a different computer the connection works as expected. How can I troubleshoot this? I tried to consult ChatGPT and follow its suggestions but it did not lead to a solution. I can also mention that I have no functioning WiFi due to driver problems so currently I access the server through a serial console (with Minicom). $ ip a 1: lo: mtu 65536 qdisc noqueue state UNKNOWN group defau0 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host noprefixroute valid_lft forever preferred_lft forever 2: end0: mtu 1500 qdisc fq_codel state UP gro0 link/ether d0:63:b4:00:97:0e brd ff:ff:ff:ff:ff:ff inet 192.168.142.34/24 brd 192.168.142.255 scope global dynamic end0 valid_lft 6341sec preferred_lft 6341sec inet 192.168.142.32/24 brd 192.168.142.255 scope global secondary end0 valid_lft forever preferred_lft forever inet6 2a02:aa1:1158:d95a:d263:b4ff:fe00:970e/64 scope global dynamic mngtmp valid_lft forever preferred_lft forever inet6 fe80::d263:b4ff:fe00:970e/64 scope link valid_lft forever preferred_lft forever 3: wlan0: mtu 1500 qdisc fq_codel s0 link/ether 4c:aa:16:fe:ca:f7 brd ff:ff:ff:ff:ff:ff $ uname -a Linux server 6.1.0-37-armmp #1 SMP Debian 6.1.140-1 (2025-05-22) armv7l GNU/Linx **Requested additional information:** $ ip route 0.0.0.0 dev end0 scope link default dev end0 scope link 37.247.0.55 dev end0 scope link 37.247.0.56 dev end0 scope link 192.168.142.0/24 dev end0 proto kernel scope link src 192.168.142.34 $ sudo traceroute 8.8.8.8 traceroute to 8.8.8.8 (8.8.8.8), 30 hops max, 60 byte packets 1 * * * 2 * * * 30 * * * $ networkctl WARNING: systemd-networkd is not running, output will be incomplete. IDX LINK TYPE OPERATIONAL SETUP 1 lo loopback - unmanaged 2 end0 ether - unmanaged 3 wlan0 wlan - unmanaged 3 links listed. $ ls /etc/network/interfaces* /etc/network/interfaces /etc/network/interfaces.bak /etc/network/interfaces.d: $ cat /etc/network/interfaces # This file describes the network interfaces available on your system # and how to activate them. For more information, see interfaces(5). source /etc/network/interfaces.d/* # The loopback network interface auto lo iface lo inet loopback # The primary network interface allow-hotplug end0 iface end0 inet dhcp