AMD 4.4.5 user manual Mediator Daemon, Switch Description

	AMD Confidential
User Manual	November 21st, 2008

the NIC model to retry a mediator connection or search for any simulator peers, running in the same process.

7.24.2 The Mediator Daemon

The mediator provides several services for the simulator session:

∙Access to real network resources (DHCP servers, etc.). Note that the mediator will need to be run with supervisor privileges in order to snoop network traffic on its host.

∙Bridge communication to other simulator sessions.

∙Group individual sessions into domains so that identical BSD‟s (with identical

MAC/IP pairs) can be run simultaneously in separate domains.

∙Provides an optional gateway to block broadcast traffic and to perform Network

Address Translation (NAT) on identical BSD‟s in different domains.

The mediator can route traffic to and from the real network. This operation requires low- level kernel actions, so the mediator must be run by a supervisor with sufficient OS privileges. Users may want to have one machine on the subnet dedicated to running the mediator in this mode. Client machines that connect to the mediator will not require supervisor privileges.

The mediator is capable of grouping certain simulator sessions into domains. Domains isolate groups of simulator sessions from each other. This can be useful when the user wants to run replicated groups of BSD‟s simultaneously. The user need to ensure that each group of BSD‟s are using unique domains in the mediator by passing an appropriate connect string to the mediator or supplying it on the command line using the “-m” option, see Section 5.1, Command-Line Arguments, on page 39.

The mediator can provide one or more gateways to isolate broadcast traffic from your simulation environment. A gateway will perform NAT in order to ensure that BSD‟s in different domains get their packets routed appropriately. The simulator sessions using the mediator‟s gateway can continue to access network resources, but are essentially hidden from the real network.

Table 7-9shows command line switches that the mediator accepts:

Switch	Description
-p portNum	Dictates what port number the mediator will be listening on for
	incoming traffic. It specifies the base port address used by the
	mediator, and port usage is based off of this number. The
	mediator's listening thread uses portNum + 4.
-l	Lists possible host adapters that the mediator can use to snoop real
	network traffic.
-s	Tells the mediator to snoop real network traffic. Requires
	supervisor privileges.
-d DeviceNum	Tells the mediator which host adapter to use when snooping real

126 Chapter 7: Device Configuration