Chapter 40 Ethernet Loopback Test (netlbtest)

The netlbtest replaces the gemtest previously included in SunVTS. It provides functional test coverage of the devices whose device drivers support the Ethernet loopback test. These include eri (the Ethernet device in the RIO chip) and ge (Gigabit Ethernet), and ce (GigaSwift Ethernet) . It runs in loopback (external/internal) mode.

The netlbtest uses DLPI RAW mode to talk to the device driver. For the purpose of this test, a packet is defined as an Ethernet header followed by the Ethernet data payload (refer to the IEEE 802.3z standard). The test generates and sends out the desired number of packets (a tunable parameter) and expects to receive the same number of packets through the loopback interface, external or internal. If an error occurs (for example, packet mismatch or timeout), an error message indicating the type of error, its probable cause(s) and recommended action(s) is displayed on the SunVTS console.The data sent out is generated by a random number generator, and put into a data buffer. Each time the packet sent is selected from a different starting point of the data buffer, so that any two consecutively transmitted packets will not be the same.

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Note -

Do not run nettest and netlbtest at the same time or the tests may fail.

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netlbtest Test Requirements

You must have the Ethernet card and the device driver installed, a loopback connector in place, and Intervention mode enabled before running netlbtest. Even though the netlbtest does not depend on the network interface configuration status of the Ethernet interface, the interface should be brought down with the ifconfig command (refer to the ifconfig(1M) man page) to avoid erroneous messages.

To run netlbtest, a loopback connector must be connected to the Ethernet interface. netlbtest cannot run if the network interface is connected to a live network, however the link must be up. A loopback connector provides the network interface driver the necessary link for testing, while maintaining isolation from a live network. The loopback connector is required for both internal and external tests of the Ethernet device.

The loopback cable for ge is based on the following specifications: multimode, duplex, 62.5/125 micron, sc connector, 850nm. The cable can be made by splitting a standard fiber optic cable in two. The two ends of the cable should be connected to the TX and RX ports of the adapter (the order does not matter), thus forming a loop.

The loopback connector for the eri device is a standard RJ45 connector. See "Twisted-Pair Ethernet (TPE) Loopback Cable" for the diagram.

netlbtest also requires that the eri device be configured offline before running the test. Type the following two commands at the command prompt:

# ifconfig ge0 down # ifconfig ge0 unplumb

netlbtest Options

To reach the dialog box below, right-click on the test name in the System Map and select Test Parameter Options. If you do not see this test in the System Map, you might need to expand the collapsed groups, or your system may not include the device appropriate to this test. Refer to the SunVTS User's Guide for more details.

Figure 40-1 netlbtest Test Parameter Options Dialog Box

Refer to Table 40-1 for test parameter descriptions.

Table 40-1 netlbtest Options

netlbtest Options	Description
Configuration	Specifies the Port Address, Host ID, and Domain Name of the system under test.
Total Packets	Specifies the total number of the packets to send. The default number of packet is 1000.
Packet size	Determines the size (in bytes) of the packets to be transmitted.   60 <= packet size <= 1514. The default packet size is 1000 bytes.
Loopback	Determines the external and internal loopback mode. The default setting is internal loopback mode.
Print_Warning	Enables or disables the printing of warning messages. The default setting is Disable.
Processor Affinity	Binds the test to a specific processor. If no processor is specified, the test migrates between processors. This option is only available on multiprocessor systems.

netlbtest Test Modes

Table 40-2 netlbtest Test Modes

Test Mode	Supported?	Description
Connection	No	Not supported.
Functional (Offline)	Yes	Runs the full set of subtests. It is assumed that the host is not connected to the network through the intended test device(s).

Since netlbtest requires a loopback connector, it can only be selected when Intervention mode is enabled.

netlbtest Command-Line Syntax

/opt/SUNWvts/bin/netlbtest standard_arguments -o dev=device,tpkts=n,pksz=pkt_size,lb=Internal ,warn=Disable

Table 40-3 netlbtest Command-Line Syntax

Argument	Description
dev=device_name	Specifies the device to test such as ge0 or eri0.
tpkts=n	[1...100000], count of packets to loopback.
pksz=pkt_size	[60... 1514], packet size in bytes.
lb=Internal	Selects internal (or external) loopback mode.
warn=Disable	Enables or disables printing of warning messages.

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Note -

64-bit tests are located in the sparcv9 subdirectory: /opt/SUNWvts/bin/sparcv9/testname. If a test is not present in this directory, then it may only be available as a 32-bit test. For more information refer to "32-Bit and 64-Bit Tests".

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