User`s guide
13
The DNS conversation is only active when PING test is run in the
DHCP On mode because the DNS IP address is only available from
the DHCP server. (Note that if known, the DNS server IP address
can be entered as a Target and PINGed like any other Target.)
The DNS server can be local or remote, like a Target. The DNS
conversation status is similar to a Target conversation status.
In most small LAN congurations, the DNS server will be a remote
device, and successful PINGing to it will verify proper LAN operation
and Internet connectivity.
The tester will shut off automatically about 15 minutes after the
last button press. The user can also terminate the test by pressing
the CABLE, NTWRK or PWR buttons. In any of these cases, the
LanScaper will issue a DHCP release request to the DHCP server
when in DHCP On mode. This is preferable to simply disconnecting
the cable to terminate the test because the address assigned to the
LanScaper™ will not be available for assignment to another device.
3.3.3 Validate Link
This mode allows two LanScaper™ testers to be connected directly
to each other on a cable with no other equipment required. No
special conguration of the testers is required other than to put
them into the test modes as described. This allows a cable run to
be veried after installation. One LanScaper™ is put into Validate
Link mode (Validator), while the other one is put into PING test with
DHCP Off (PING Generator). The Validator will be locked in NIC
mode, generating link pulses that the PING Generator can receive
to allow it to take on the HUB cable conguration. Once the PING
Generator detects the Link pulses, it will go into the active PING
state and start generating ARP packets, attempting to connect to
both the manually congured Target and Router IP addresses.
The Validator will receive the ARP requests, and wait until it gets
several requests for the same IP address, while not receiving any
responses from another device to that IP address. The Validator will
then assume that IP address, and respond to the ARP. The PING
Generator then starts to PING the IP address that the Validator has
responded to. The Validator responds to the PING, but modies
the packet instead of merely copying it, so that the PING Generator
can recognize when it is communicating with a Validator. When the
PING Generator recognizes the Validator’s response, it will change
it’s PING status acronym display to “Val”, and terminate the PING
conversation to the other IP address it is congured for. Once this
negotiation is complete, the Validator will show a count of PINGs
received, and the PING Generator will display the normal PING
status screens for monitoring the progress of the test.