Collecting data for network problems

If the network has a problem, collect diagnostic data that you can use to diagnose and resolve the problem.

Procedure

To collect diagnostic data for network diagnostics:

Provide a diagram of your network setup.
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
```
Some environments might have special routing rules that must be considered:
```
ip rule list
```
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
# nft list tables
# nft list ruleset
# nft list chains

Note: sudo nft list tables 
```
Additionally, there can be NAT-rules. To list them, issue:
```
# iptables -t nat -vnL
```
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.
Attach the data files to the opened support case.