X Mcast Plugin - Technical Reference

Introduction

The Geneos X Mcast plugin monitors multicast traffic and displays statistics such as the data rate and packet rate, for a list of user-defined multicast groups.

This plugin differs from the X Multicast plugin in that it can monitor for multicast data without necessarily subscribe for it, and also does not need to read and discard data so is slightly more efficient.

The Netprobe host must be able to "listen" for the required multicast traffic (i.e. it should be on the same network segment as a host already subscribing to the required multicast data).

Views

View

The X Mcast plugin produces a single view, with one row per configured multicast session.

Headline Legend

Name	Description
totalDataRecvRate	Data receive rate for all monitored sessions.
totalPktRecvRate	Packet receive rate for all monitored sessions.

Table Legend

Name	Description
name	The session name, as configured by the user.
port	The session port, as configured by the user.
dataRecvRate	Data received in Kb/s, averaged over the sample interval.
pktRecvRate	Packets received per second, averaged over the sample interval.
tmSinceLastPkt	Number of seconds since the last packet was received.
srcHost	The IP address of the host which sent the last packet.

Plugin Configuration

The X Mcast plugin listens to all multicast data received by a host, matching the destination host and ports with those configured by the user.

Plugin configuration is placed in the x-mcast configuration section.

var-recvInterfaces

Specifies a comma-separated list of network interface names on which to monitor multicast data.

On UNIX machines, interface names can be found using the command "ifconfig -a". Example names are "eth0" or "ce0".

On Windows machines, interface names can be listed by running Netprobe using the "-ifconfig" command-line option. A Windows interface name will look similar to the following:

\Device\NPF_{BDFE3EAC-0275-440A-923C-C9C4CE3B37F2}

Mandatory: Yes

sessions

Specifies the list of (at least one) multicast sessions that this plugin will monitor.

Mandatory: Yes

sessions > session > var-name

The name of the multicast session - this is the name which will be displayed in the view (as the row name). Session names should be unique within each plugin instance.

Mandatory: Yes

sessions > session > connection

Specifies the multicast address and port for the session - multicast packets received for this connection will be added to the monitoring statistics for this session.

Mandatory: Yes

Permissions

The plugin needs to open network devices, so you should run the Netprobe using root or administrator permission on Unix and Windows, respectively.

On Linux kernel versions 2.6.24 and higher, an alternative to running the Netprobe as root is by setting the CAP_NET_RAW and CAP_NET_ADMIN Linux capabilities on the Netprobe binary using the following command:

setcap cap_net_raw,cap_net_admin+eip <netprobe binary>

When running the Netprobe with set capabilities, the lib64 folder in the Netprobe directory should be in the ld.so trusted paths. Otherwise, the runtime libraries will not load properly. For guidance, see Run Netprobe under elevated privileges in Linux in Quickstart: Linux and other platforms.

Third Party Libraries

Windows: The Winpcap packet capture library (http://www.winpcap.org/install/default.htm) needs to be installed on the host. Version 4.0.2 is required for Windows Vista/Server 2003 support.

Unix: The shared library libpcap.so (version 1.0.0 or later is recommended) needs to be in the netprobe lib64 directory.

Note: As the netprobe needs to be run as root the LD_LIBRARY_PATH is ignored for security reasons.