Troubleshooting guide

3-2
ATM and Layer 3 Switch Router Troubleshooting Guide
OL-1969-01
Chapter 3 Initial Troubleshooting
Online Diagnostics
Note The size of the packet and frequency of the test are configurable to minimize the impact on system
performance.
Accessibility Test
The accessibility tests ensure connectivity, at a configurable interval, between all of the following:
• Interface modules
• Active switch processor
• Standby switch processor, if it is present
OIR Test
Online insertion and removal (OIR) tests check the functioning of the switch fabric and interfaces on a
per-port basis. The switch router performs these tests when the system boots up and when you insert an
interface module into a slot. The OIR test sends a packet to the interface loopback and expects to receive
it within a certain time period. If the packet does not reach the port within the expected time period, or
the received packet is corrupted, an error is registered and the port is changed to an administrative down
state. Packets that are 1000 bytes in size are used in the test.
The OIR tests support all the enhanced Gigabit Ethernet interface modules, with the exception of the
OC-3c and OC-12c ATM uplink interface module. In addition, OIR tests are not supported on the Fast
Ethernet or Gigabit Ethernet interface modules.
OIR is enabled by default on the Catalyst 8540 CSR. To disable it, enter the no diag online oir
command. To enable OIR, see to commands in the “Configuring Online Diagnostics
(Catalyst 8540 CSR)” section on page 3-2.
Snake Test
The snake test detects and reports port-to-port connectivity failures. The snake test establishes
connections across all the active ports in the switch router, originating and terminating at the primary
route processor. The route processor establishes a connection by sending a packet to each port in turn,
which then terminates at the route processor. If the packet does not reach the route processor within the
expected time period, or the received packet is corrupted, further testing is performed to isolate and
disable the port causing the problem. The frequency of the test is configurable to minimize the impact
on system performance.
The snake test supports all the enhanced Gigabit Ethernet interface modules on the Catalyst 8540 MSR
and Catalyst 8540 CSR.
Configuring Online Diagnostics (Catalyst 8540 CSR)
To configure online diagnostics, use the following global configuration commands:
Command Purpose
diag online Enables all of the online diagnostic tests.
diag online access Enables only the accessibility diagnostic test.