Management and Configuration Guide K/KA/KB.15.15

• When debugging is finished and the no debug all command is entered, the commands being
sent to the previously configured Syslog server(s) are not affected, and no additional commands
are needed. If both debug event and debug destination logging are configured, duplicate
events are not sent to the configured Syslog servers.
• The show debug command won’t display debug event or debug destination logging unless
the debug event command is executed for buffer or session destinations.
• You can check on the configured Syslog settings with the show syslog config command. The
Syslog settings also are visible in the output of show running-config or show startup-config.
Diagnostic tools
Port auto-negotiation
When a link LED does not light (indicating loss of link between two devices), the most common
reason is a failure of port auto-negotiation between the connecting ports. If a link LED fails to light
when you connect the switch to a port on another device, do the following:
1. Ensure that the switch port and the port on the attached end-node are both set to Auto mode.
2. If the attached end-node does not have an Auto mode setting, you must manually configure
the switch port to the same setting as the end-node port. See Chapter 10, "Port Status and
Configuration".
Ping and link tests
The ping test and the link test are point-to-point tests between your switch and another IEEE
802.3-compliant device on your network. These tests can tell you whether the switch is
communicating properly with another device.
NOTE: To respond to a ping test or a link test, the device you are trying to reach must be IEEE
802.3-compliant.
Ping test
A test of the path between the switch and another device on the same or another IP network that
can respond to IP packets (ICMP Echo Requests.) To use the ping (or traceroute) command
with host names or fully qualified domain names.
Link test
A test of the connection between the switch and a designated network device on the same LAN
(or VLAN, if configured.) During the link test, IEEE 802.2 test packets are sent to the designated
network device in the same VLAN or broadcast domain. The remote device must be able to respond
with an 802.2 Test Response Packet.
Executing ping or link tests (WebAgent)
To start a ping or link test in the WebAgent:
1. In the navigation pane, click Troubleshooting.
2. Click Ping/Link Test.
3. Click Start.
4. To halt a link or ping test before it concludes, click Stop.
426 Troubleshooting