Black Box TS560A, User Manual

Page: 37 / 67

34
LAN SOLUTION NETWORK TESTER
its proposed MyIP address. A response to the ARP tells
the tester that some other device on the LAN is already
using that IP address.
The DHCP protocol specification (RFC 1541) says that
when a server offers an address already in use, the
receiver of that address should reject it and request
another. The LAN Solution Network Tester does not
inform the server about the conflict, but it does report it
on the LCD: “My IP in use on this network.” If this is
found, the tester will not continue into the PING state
because using another device’s IP address is not
permissible on a LAN. This condition shows that the
DHCP server is misconfigured. The tester will restart
from this state automatically after one minute, or it can
be manually restarted to retry the test. If multiple retries
end up unsuccessful, the tester must be manually
configured and used in the DHCP Off mode. In this
case, the LAN configuration parameters can be seen in
Setup mode in the Last DHCP submenu. This will also
include the IP address offered to the tester.
After successfully receiving a valid IP address, the
operation of the tester continues with the PING state
(see page 36).