`Net`

Network Manager (QNX)

Syntax:

Net [options]... &

Never automatically add network mappings for previously unmapped machines which attempt to communicate with this node. (Default is to automatically learn new network mappings when previously unknown nodes initiate communication with this node.)

-b brk_buf_numk

The amount of RAM (in kbytes) to be allocated for bridge packet buffers. (Default is 64) This memory won't actually be allocated until the first brouted packet arrives at this node.

-C

Don't maintain "netmap" node/driver transmit counts

-d num_drivers

The maximum number of network drivers that may be registered with Net at any one time (default is 2).

-e num_log_elements

The number of elements in the runtime error log used by the Network Manager and the network drivers (default is 200).

-E mask

Inhibit netinfo logging messages as follows:

-E 1: filters out "unrecognized raw protocol" message.
-E 2: filters out "netmap change" message.
-E 3: filters out both.

-L name

Choose name to attach to. Default is qnx/net.

-m mapping

A logical-to-physical node ID mapping that is preloaded by Net. The mapping contains three fields: the first is a logical node ID; the second, a logical network ID; and the third, a physical network card ID (address). Multiple -m options are permitted. Note that a node always knows its own logical node ID ( Process Manager -l ("el") parameter), logical network ID (network driver -l ("el") parameter), and physical network ID (obtained by a network driver from the hardware).

-n num_nodemap

The number of nodemap elements (default is the number of nodes in the OS license). These are used to cache logical-to-physical node mapping information. One element is required per remote node being communicated with at any time.

-q num_qpkts

The number of elements in the Process Manager to Network Manager nonblocking queue (default is 2* the maximum number of processes specified to Proc32). You should need to use this option only in the unlikely event that the Process Manager runs out of elements. The more virtual circuits a node will have, the more elements it will require.

-r num_raw

The number of raw protocols that may be registered with Net for reception of raw data by processes (default is 16).

-R

Retry replies until connection is gone. Default is to not attempt to retry replies.

-S

Allow raw apps to take over previously registered protocols. For example, you could temporarily usurp TCP/IP, then relinquish it.

-t tx_fail_time

The number of seconds a network driver will be "avoided" by the Network Manager if the driver fails to transmit to a particular node (default is 40). This is relevant only when multiple networks are being used.

-T

Don't log runtime errors to the trace log (traceinfo); use the built-in netinfo log only.

-v

Be verbose. If a runtime error occurs in Net or in any network driver, a message with an error code will be displayed on the console. This option is normally used only for debugging.

Description:

The Net manager provides services that the Process Manager and Kernel require to provide transparent networking. It does this via network drivers. The Network Manager is typically built into an operating system image or started in the sysinit file; it is rarely started from the command line. If you experience any problems, you should run the netinfo utility to get information about recent significant network events and errors.

Don't change the priority of Net or of a Net.* driver -- unexpected behavior may result if you do!

The versions of Net in QNX 4.23 and later support "brouting," a QNX-to-QNX bridge/routing scheme which allows QNX nodes on different physical IEEE 802-based networks to talk to one another through a common node or nodes which are connected to both networks. This scheme is described in detail in the technical note /etc/readme/technotes/Net_brouting available on QUICS.

Brouting is automatic if the network maps (see netmap) are properly configured on all nodes. To work, the following conditions must be met:

each physical network present has been assigned a unique network number for use in the netmap table. (e.g. you can't have a net 1 bridged to another net 2 which is in turn bridged to a second net 1)
each network node on any of the physical networks has a unique node number (e.g. you can't have a node 1 on net 1 and a node 1 on net 2)
each node has a complete netmap table which declares all the nodes on all the networks, even if that particular node does not have a direct connection to all the physical networks

There is additional mention of the network mapping requirements for brouting in the documentation for the netmap utility.

Examples:

Start the Network Manager, with defaults:

   Net &

Support a node which will have 3 network cards installed:

   Net -d 3 &

Run net with an increased error log size:

   Net -e2000 &

Don't log trace events:

   Net -T &

Support a node which must boot up already knowing the network mapping to node 1, since it is booting across the network using a boot ROM and needs to be able to talk to node 1 to obtain the system initialization file and binaries necessary to complete its startup:

   Net -m "1  1  0000C0 469330" &

This example lets Net preload its mapping table with the information that logical node ID 1 may be reached via logical network 1 (which must be the same as the network driver's) by transmitting to physical address 0000C0 469330. This allows the node to execute the sysinit.node file on node 1, which contains the netmap utility. The netmap utility will open a node mapping file located on the server (node 1) and then tell Net about all of the other logical-to-physical node mappings found in this mapping file.

The physical address in the above example is a 48-bit IEEE 802 address. Some network hardware supports less than 48 bits. For example, in the case of Arcnet, the physical address length supported is only 8 bits, so the third field would consist of only one byte. By default, the physical address is assumed to be in hex, but for Arcnet you can specify an 8-bit address in decimal if you prefix the address with a t (e.g. t1). For more information, see the netmap utility.

Signals:

The Net manager ignores SIGPWR.

Exit status:

0: Successful completion.
>0: An error occurred.