Tips for using mmprotocoltrace

Follow these tips for mmprotocoltrace.

Specifying nodes with the -N and -c parameters.

It is important to understand the difference between the -N and -c parameters of the mmprotocoltrace command:

The -N parameter specifies the CES nodes where you want tracing to be done. The default value is all CES nodes.
The -c parameter specifies the IP addresses of clients whose incoming connections are to be traced. Where these clients are connected to the CES nodes that are specified in the -N parameter, those CES nodes trace the connections with the clients.

For example, in the SMB trace started by the following command, the CES node 10.40.72.105 traces incoming connections from clients 192.168.4.1, 192.168.4.26, and 192.168.4.22. The command is all on one line:

mmprotocoltrace start smb -c 192.168.4.1,192.168.4.26,192.168.4.22 
          -N 10.40.72.105

Discovering client IP addresses for an smb trace

If you have only a few clients that you want to trace, you can list their IP addresses by running the system command smbstatus on a CES node. This command lists the IP addresses of all smb clients that are connected to the node.

However, if many clients are connected to the CES node, running smbstatus on the node to discover client IP addresses might not be practical. The command sets a global lock on the node for the entire duration of the command, which might be a long time if many clients are connected.

Instead, run the system command ip on each client that you are interested in and filter the results according to the type of device that you are looking for. In the following example, the command is run on client ch-41 and lists the IP address 10.0.100.41 for that client:

[root@ch-41 ~]# ip a | grep "inet "
    inet 127.0.0.1/8 scope host lo
    inet 10.0.100.41/24 brd 10.255.255.255 scope global eth0

A client might have more than one IP address, as in the following example where the command ip is run on client ch-44:

[root@ch-44 ~]# ip a | grep "inet "
    inet 127.0.0.1/8 scope host lo
    inet 10.0.100.44/24 brd 10.255.255.255 scope global eth0
    inet 192.168.4.1/16 brd 192.168.255.255 scope global eth1
    inet 192.168.4.26/16 brd 192.168.255.255 scope global secondary eth1:0
    inet 192.168.4.22/16 brd 192.168.255.255 scope global secondary eth1:1

In such a case, specify all the possible IP addresses in the mmprotocoltrace command because you cannot be sure which IP address the client will use. The following example specifies all the IP addresses that the previous example listed for client ch-44, and by default all CES nodes will trace incoming connections from any of these IP addresses:

mmprotocoltrace start smb -c 10.0.100.44,192.168.4.1,192.168.4.26,192.168.4.22