Browser Connection Troubleshooting - D-Link NetDefend SOHO DFL-160 User Manual

2.3. Browser Connection
Troubleshooting

2.3. Browser Connection Troubleshooting

If the management interface does not respond after the DFL-160 has powered up and NetDefendOS
has started, there are a number of simple steps to trouble shoot basic connection problems:
1. Check that the LAN interface is being used
The most obvious problem is that the wrong DFL-160 interface has been used for the initial
connection. Only the LAN interface is enabled for management access for the initial connection
from a browser after NetDefendOS starts for the first time.
2. Is the LAN interface properly connected?
Check the link indicator lights on the management interface. If they are dark then there may be a
cable problem.
3. Check the cable type connected to the management interface.
If the management interface is connected directly to the management workstation or another router
or host? In this case, an Ethernet "cross-over" cable may be needed for the connection, depending on
the capabilities of the interface.
4. Using the ifstat CLI command
To investigate a connection problem further, connect a console to the RS232 port on the DFL-160
after NetDefendOS starts. The details of making this connection are described below in Section 2.4,
"Console Port Connection".
When you press the enter key, NetDefendOS should respond with the standard CLI prompt:
DFL-160:/>
Now enter the following command a number of times:
DFL-160:/> ifstat lan
This will display a number of counters for the LAN interface.
If the Input counters in the hardware section of the output are not increasing then the error is likely
to be in the cabling. However, it may simply be that the packets are not getting to the DFL-160 in
the first place. This can be confirmed with a packet sniffer if it is available.
If the Input counters are increasing, the LAN interface may not be attached to the correct physical
network. There may also be a problem with the routing information in any connected hosts or
routers.
5. Using the arpsnoop CLI command
A final diagnostic test is to try using the console command:
DFL-160:/> arpsnoop -all
This will show the ARP packets being received on the different interfaces and confirm that the
correct cables are connected to the correct interfaces.
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Chapter 2. Initial Setup