Cabletron Systems Netlink FRX8000, User Manual

Page: 393 / 468

Chapter 22
Tests
Tracing a Packet
This operation traces the path a packet takes through the network. The procedure sends
one or more trace packets from a source node to a destination node. Event log mes-
sages tell you which intermediate nodes each packet passes through as it travels to its
final destination.
Here is the format of the printer messages:
(Date)(Time) TRACE source: “n”s dest: “n”d “n” current: “n”c
where:
TRACE
indicates that this is a packet trace.
source:“n”s
is the ID of the source node.
dest: “n”d
is the ID of the destination node.
seq#: “n”
is the segment number. Each time the trace packet arrives at a
node on its way to the destination node, the segment number
value is increased by one. Refer to the examples below for
further explanation.
current: “n”c
is the current position of the trace packet in the network (“n”c
is a node ID). When the current
“n”c
value is the same as the
destination
“n”d
value, the trace packet has arrived at its
intended destination.
Here is an example of a series of packet trace messages:
971208 112947 TRACE source: 1 dest: 4 seg: 1 current: 2
971208 112947 TRACE source: 1 dest: 4 seg: 2 current: 3
971208 112947 TRACE source: 1 dest: 4 seg: 3 current: 4
This packet trace was performed on December 8, 1997 at about 11:30 a.m. The source
node specified by the operator was node 1 and the destination node was 4. The trace
packet was routed through nodes 2 and 3 to reach node 4. Notice that the segment
numbers kept a count of how many nodes recorded the path of the trace packet.
To initiate or discontinue a packet trace, press
[D]
at the Tests Menu (or
[E], [D]
from
the Main Menu). When prompted, enter:
●
Source Node ID
:
1–250
.
●
Destination Node ID
:
1–250
.