20-19
Catalyst 6500 Series Switch Software Configuration Guide—Release 8.7
OL-8978-04
Chapter 20 Checking Status and Connectivity
Using System Warnings on Port Counters
To determine when a datagram reaches its destination, traceroute sets the UDP destination port in the
datagram to a very large value that the destination host is unlikely to be using. When a host receives a
datagram with an unrecognized port number, it sends an ICMP port unreachable error to the source. This
message indicates to the traceroute facility that it has reached the destination.
The switches can participate as the source or destination of the
traceroute
command but will not appear
as a hop in the
traceroute
command output.
Executing IP Traceroute
To trace the path that the packets take through the network, perform this task in privileged mode:
This example shows how to use the
traceroute
command:
Console> (enable)
traceroute 10.1.1.100
traceroute to 10.1.1.100 (10.1.1.100), 30 hops max, 40 byte packets
1 10.1.1.1 (10.1.1.1) 1 ms 2 ms 1 ms
2 10.1.1.100 (10.1.1.100) 2 ms 2 ms 2 ms
Console> (enable)
This example shows how to perform a
traceroute
with six queries to each hop with packets of 1400 bytes
each:
Console> (enable)
traceroute -q 6 10.1.1.100 1400
traceroute to 10.1.1.100 (10.1.1.100), 30 hops max, 1440 byte packets
1 10.1.1.1 (10.1.1.1) 2 ms 2 ms 2 ms 1 ms 2 ms 2 ms
2 10.1.1.100 (10.1.1.100) 2 ms 4 ms 3 ms 3 ms 3 ms 3 ms
Console> (enable)
Using System Warnings on Port Counters
You can monitor and troubleshoot the Catalyst 6500 series switches by polling the selected error
counters on the ports and logging the system error messages. The messages are logged for the system,
hardware, and spanning-tree ports for these conditions:
•
Backplane traffic levels that exceed configurable thresholds
•
Low remaining memory
•
Detected memory corruption
•
NVRAM logs
•
Inband errors
•
User Datagram Protocol (UDP) and TCP errors
The hardware error information is logged to provide information for the debug port counters at
30-minute intervals. The messages are logged if the counter values increase.
Task
Command
Execute IP traceroute to trace the Layer 3 path
that the packets take through the network.
traceroute
[
-n
]
[
-w
wait_time
]
[
-i
initial_ttl
]
[
-m
max_ttl
]
[
-p
dest_port
]
[
-q
nqueries
]
[
-t
tos
]
host
[
data_size
]