Collecting data for network problems

To collect diagnostic data for network diagnostics:

1. Provide a diagram of your network setup.
2. Use netstat to collect diagnostic data.
   Note: netstat is deprecated as of SUSE Linux® Enterprise Server 15. Use the socket statistics command ss -r instead, see ss - Display sockets statistics .
3. Collect IP network configuration data, for example, by issuing ip a l for the IP network configuration and ip r l for the routing tables:

   # ip a l
   # ip r l

4. Some environments might have special routing rules that must be considered:

   ip rule list

5. A typical network connection might be restricted by firewall rules and, thus, existing rules should also be reported.
   For example, list rules and the default policy by issuing:

   # iptables -vnL

   Additionally, there can be NAT-rules. To list them, issue:

   
   # iptables -t nat -vnL

6. A slow network is sometimes due to an incorrect DNS configuration. Check if the DNS servers are configured and reachable. Issue a host or dig command. The ping command might not always work due to firewall rules.
7. Attach the data files to the opened support case.