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Chapter 5 AN100U/UX Troubleshooting
Redline Communications Inc. Confidential and Proprietary
Configuring the AN100U/UX for Management via the Management Port
Configure the AN100U/UX for separated management, which will enable an Ethernet
connection with the management port.
Step 1
Login to the Web client as outlined in “Connecting to the Sector Controller Web Client” on
page 2-4.
Step 2
From the Main menu select Interface Configuration > Ethernet.
The Ethernet Interface page is displayed. You can review this page to view the
configuration of the device’s Ethernet interface.
Step 3
Check the value of Management. This parameter should be set to Via Mgt port, then
device management will be done out of band via the management port.
Step 4
Select Via Mgt port and click Save to make the changes and return to the main menu.
Duplex Mismatch
Duplex conflicts are a common source of performance degradation. This problem is easy
to correct but difficult to identify and localize.The issue may recur, as interfaces go up and
down over time and network elements are upgraded and replaced.
Ethernet devices with different speeds and duplex modes can exist on the same physical
network. Auto-negotiation is a protocol that allows two devices to agree on the highest
possible speed that both devices can support. Both devices advertise all of their supported
speed and duplex combinations and the highest, common set is selected and used by both
devices.
This only works if both devices support auto-negotiation. If only one device supports the
feature, and the other device has a fixed configuration, one device will recognize the speed
of the remote end, but it will not be able to recognize whether the remote end operates in
half or full duplex mode. It will, according to the standard, always assume half duplex
mode.
A typical error is to configure one side of the link for full duplex, and the other one for
auto-negotiation. This combination will result in a duplex mismatch, which causes a lot of
collisions and bad frames. The link will work, but the end-user will experience erratic
behavior, especially if their traffic is delay-sensitive. If you test the connection using the
ping utility, you may sometimes see no loss, while at other times you may see up to 60%
loss on a 100 Mbps path.
When collisions occur, the device that is configured for half-duplex mode will detect it, send
the "jamming signal", discard the received frame, and prepare its own packet for
re-transmission. The problem is that the device is configured for full-duplex mode ignores
the jamming signal, so the packets that it was sending are lost.
In the case of a duplex mismatch, you can expect to see many collisions reported on the
half-duplex side, and a lot of received error frames on the full-duplex side.
