Troubleshooting VM network problems using IP Fabric CLI
In the event of a VM network connection problem, DNS issues, network devices connectivity issue, IP Fabric CLI is a useful helper.
CLI can be also used to access system and application logs as well as snapshot files.
System and application logs
System and application logs are placed in /var/log folder. Specifically IP Fabric application logs can be found in /var/log/nimpee.
Snapshots are available in osadminhome directory /home/osadmin/snapshots. Each folder inside represents one snapshot. Even if snapshots can be copied manually using SCP or SFTP it's strongly recommended to use the export feature in web UI.
Checking the network interface settings
When you log in through a VM console or SSH, network settings are displayed.
This content is static, generated when VM boots! When DHCP is used, an IP address can change in some cases.
To display actual IP address use command:
ip addr show
Default gateway and other routes (if configured) can be check as follows:
DNS can be checked using the digor nslookupcommand.
For example, let's check A record and PTR (reverse) record of some device using dig.
For A record check ANSWER which contains requested IP address. Also SERVERsection below is important as it tell us what DNS server answered our DNS query.
For PTR record check ANSWER which contains requested domain name.
If you prefer nslookupyou can achieve the same results.
Testing connectivity to a network device
The very basic test is pingor traceroute.
Please bear in mind that ICMP packets used by pingand traceroutecan be blocked by ACL or firewall. It does not mean that a device cannot be reached using SSH or telnet.
To make sure that the network device is available from IP Fabric VM, you can use the telnetand sshclient from the command line.
For SSH use:
For telnet use:
Reboot and shutdown
IP Fabric VM can be also rebooted or shutdown using CLI.
For VM reboot just use rebootcommand without any parameters.
For VM shutdown use shutdowncommand without any parameters.