How can network errors in Linux systems be checked and diagnosed?

To check and identify the causes of network errors in Linux, you can use the following tools and methods:

• ping — check the availability of a remote host and measure response time.
• traceroute — determine the route to a remote node and identify bottlenecks.
• netstat or ss — view active network connections and port statuses.
• tcpdump — capture and analyze network packets for detailed traffic examination.
• iftop or nload — monitor current network load.
• dmesg — view system messages related to network drivers and hardware.
• Check network interface configurations using ip addr, ip route.

It is also important to check firewall settings (iptables, nftables), DNS (via dig or nslookup), and application logs that use the network.

Example of using ping and traceroute:

ping 8.8.8.8
traceroute 8.8.8.8