ITMS Administrator Group

If multicast is set as the default for downloading packages in the Global Agent Settings policy, this option lets you turn it off. However, individual packages may override this setting.

If the Global Agent Settings policy has multicast turned off, you cannot turn it on with this option.

The maximum number of concurrent sessions for which a Symantec Management Agent can be the master.

When a computer is a master for a single session, the overhead should not be significantly different from a computer that is simply receiving the package via multicast.

The default value is 1 for new policies and for all of the default targeted agent settings policies.

The recommended value is also 1, because the agent can download only a single package at a time. Any package download is preempted by another package of a smaller size. Note that starting from IT Management Suite versions 8.0 HF3 and 7.6 POST HF7 v7, the multicast session cannot be preempted.

For example: 5 packages of different sizes need to be redistributed. If all packages arrived to the agent during the same policy update, and all the agents need all 5 packages, first of all, the smallest package will be downloaded and distributed among the agents via multicast. The largest package will be downloaded and redistributed last, so downloading all 5 packages via multicast requires a lot of time. Only if different agents need to download a subset of these 5 packages, there could be a few different simultaneous multicast sessions made for packages of different sizes.

50% of configuration update interval, and not less than 30-45 minutes.

If you want to distribute a single package via multicast, the recommended Wait timeperiod could be slightly longer than the configuration update interval. In this case, all the agents will receive the policy during that time and will have the chance to join the same multicast session.

When more packages need to be redistributed via multicast, it is not feasible to wait for all agents to join a single session. In this situation, configure the Wait time to be 50% of the configuration update interval, so that some agents would start the session even before other agents receive the policy. The agents that receive the policy later will download the packages via another multicast session from an agent from the first multicast session.

If a session times out, the Symantec Management Agents that were members of the session attempt to download the package again through multicast until the Maximum transmission attempts per package value is reached.

The number of Symantec Management Agents (excluding the master) that must join the session to enable multicasting to begin.

This setting cannot be less than Minimum receiving computers per session. Use this setting to override theWait time to begin session option when enough agents have joined the session.

Set the value to a large number (100-200), if you want to reduce the network traffic.

If you enter a low value, a large number of small sessions will be formed. The higher number results in lower network traffic, but increased delivery time.

The maximum bandwidth that multicasting can use per package.

The multicast master begins at a slower speed and gradually increases the speed to this value if there are no errors. If the agents receiving the broadcast discover errors, they send a message back to the multicast master where it is evaluated. The multicast master can resend the data or remove the agent from the session. Alternatively, the multicast master can reduce the amount of data that is being multicast.

10MBytes/sec

Increase when delivering large (50+MB) packages and network is capable.

2

In most cases, a single attempt is sufficient. However, sometimes, the package may expire at the master.

50

The actual number of physical sessions will be much lower than 50 because of the asynchronous nature of multicast session negotiation, where agents that need to download the same package are getting to know each other over a period of time before forming a single final multicast session.

Before the session is formed, different agents can try creating a new session simply because they do not know yet that some other agent has already created another session for the same package. In a minute or two, these agents will receive that information, join the already existing session, and terminate the session they created before. In this situation, there can be a number of short-lived sessions that should be accounted for.

The more computers you have in the subnet, the larger this value should be. For example, for 200-250 computers you can increase the value to 75 or more.

Go above this value if you notice the following error in the logs: "CanDownloadPackage(): Multicast skipped, too many sessions: subnet/segment = 20"

NOTE: Do not forget to increase the range of TCP/IP Listener range on the Global Agent Settings page.

Default value.

This is the address on which the request for packages goes out. All multicast-enabled agents monitor this address for package requests.

The port number that the Symantec Management Agents use to listen to multicast messages on the network.

The TCP/IP multicast port number must be between 1024 and 65535.

The range of IP addresses from which a multicast session chooses an address to use during the multicasting of the package by the master. You can add new ranges and specify the appropriate IP addresses for each range.

There must be at least one listener IP address range specified that cannot be deleted.

Increase this range to double the number of addresses that the setting Maximum sessions per physical subnet has.

Increase this range if there are exclusion ranges.

The range of IP addresses that cannot be used for multicasting. You can add new ranges, and specify the appropriate IP addresses for each range.

The Exclusion IP address ranges can be a subset of Listener IP address ranges but not vice versa.

None.

Add only if there are other multicast operations occurring on specified addresses, or there are problems using certain addresses.