18–Running User Diagnostics in DOS
Diagnostic Test Descriptions
271
83840-546-00 N
Group D: Ethernet Traffic Tests
D1
MAC Loopback
Enables MAC loopback mode in the adapter and transmits 5000
Layer 2 packets of various sizes. As the packets are received back
by Cavium 8400/3400 Series User Diagnostics, they are checked
for errors. Packets are returned through the MAC receive path and
never reach the PHY. The adapter should not be connected to a net-
work.
D2
PHY Loopback
Enables PHY loopback mode in the adapter and transmits 5000
Layer 2 packets of various sizes. As the packets are received back
by Cavium 8400/3400 Series User Diagnostics, they are checked
for errors. Packets are returned through the PHY receive path and
never reach the wire. The adapter should not be connected to a net-
work.
D4
LSO
Verifies the adapter’s large send offload (LSO) support by enabling
MAC loopback mode and transmitting large TCP packets. As the
packets are received back by Cavium 8400/3400 Series User Diag-
nostics, they are checked for proper segmentation (according to the
selected MSS size) and any other errors. The adapter should not be
connected to a network.
D5
EMAC Statistics
Verifies that the basic statistics information maintained by the chip is
correct by enabling MAC loopback mode and sending Layer 2 pack-
ets of various sizes. The adapter should not be connected to a net-
work.
D6
RPC
Verifies the receive path catch-up (RPC) block by sending packets
to different transmit chains. The packets traverse the RPC logic
(though not the entire MAC block) and return to the receive buffers
as received packets. This is another loopback path that is used by
Layer 4 and Layer 5 traffic within the MAC block. As packets are
received back by Cavium 8400/3400 Series User Diagnostics, they
are checked for errors. The adapter should not be connected to a
network.
Table 18-2. Diagnostic Tests (Continued)
Test
Number
Test Name
Description
