Debug/Syslog for IPv6

The Debug/System logging (Syslog) for IPv6 feature provides logging functions similar to those of the IPv4 version, allowing you to record IPv4 and IPv6 Event Log and debug messages on a remote device to troubleshoot switch or network operation. For example, you can send messages about routing mis-configurations and other network protocol details to an external device, and later use them to debug network-level problems.


	NOTE: This section describes the commands for Debug/Syslog configuration in an IPv6 environment. For information on using the Debug/Syslog feature in an IPv4 environment, see “Debug/Syslog Operation” in the current Management and Configuration Guide for your switch.

Configuring debug and Event Log messaging

To specify the types of debug and Event Log messages that you want to send to an external device:

Use the debug <debug-type> command to send messaging reports for the following types of switch events:
- ACL “deny” matches
- DHCP snooping events
- Dynamic ARP protection events
- Events recorded in the switch’s Event Log
- IPv4 and RIP routing events
- IPv6 DHCPv6 client and Neighbor Discovery events
- LLDP events
Use the logging <severity severity–level | system–module system–module> command to select a subset of Event Log messages to send to an external device for debugging purposes according to:
- Severity level
- System module

Debug command

Syntax:

[no] debug <debug–type>

Configures the types of IPv4 and IPv6 messages that are sent to Syslog servers or other debug destinations, where <debug–type> is any of the following event types:

acl : When a match occurs on an ACL “deny” statement with a log parameter, an ACL message is sent to configured debug destinations. (Default: Disabled - ACL messages for traffic that matches “deny” entries are not sent.)

all : Configures all IPv4 and IPv6 debug message types to be sent to configured debug destinations. (Default: Disabled - No debug messages are sent.)

arp-protect : Configures messages for Dynamic ARP Protection events to be sent to configured debug destinations. (Default: Disabled - No debug messages are sent.)

event : Configures Event Log messages to be sent to configured debug destinations.

Event Log messages are enabled to be automatically sent to debug destinations in the following conditions:

If no Syslog server address is configured and you enter the logging command to configure a destination address.

If at least one Syslog server address is configured in the startup configuration and the switch is rebooted or reset.

Event log messages are the default type of debug message sent to configured debug destinations.

ip : Configures IPv4 RIP routing messages to be sent to configured debug destinations.

ip [rip <database|event|trigger> : Configures specified IPv4 RIP message types to be sent to configured debug destinations:

database : Database changes

event : RIP events

trigger : Trigger messages

ipv6 : Configures messages for IPv6 DHCPv6 client and neighbor discovery events to be sent to configured debug destinations.

ipv6 [dhcpv6-client <events|packets>|nd> : Configures one of the following IPv6 message types to be sent to configured debug destinations:

dhcpv6-clients events : DHCPv6 client events

dhcpv6-clients packets : Statistics on DHCPv6 packets transmitted on a switch configured as a DHCPv6 client

nd : Events during IPv6 neighbor discovery

lldp : Configures all LLDP message types to be sent to configured debug destinations.

Configuring debug destinations

An IPv6-based debug/syslog destination device can be a Syslog server (up to six maximum) and/or a console session:

Use the debug destination <logging|session|buffer> command to enable (and disable) Syslog messaging on a Syslog server or to a CLI session for the debug message types configured with the debug and logging commands (see Configuring debug and Event Log messaging).

debug destination logging : enables the configured debug message types to be sent to Syslog servers configured with the logging command.

debug destination session : enables the configured debug message types to be sent to the CLI session that executed this command. The session can be on any one terminal emulation device with serial, Telnet, or SSH access to the CLI at the Manager level prompt.

debug destination buffer : enables the configured debug message types to be sent to a buffer in switch memory.

Logging command

Syntax:

[no] logging <syslog–ipv4–address|syslog-ipv6-addr>

Enables or disables Syslog messaging to the specified IPv4 address. You can configure up to six addresses. If you configure an address when none are already configured, this command enables destination logging (Syslog) and the Event debug type. Therefore, at a minimum, the switch begins sending Event Log messages to configured Syslog servers. If other debug message types are configured, they are also sent to the Syslog server.

no logging : Removes all currently configured Syslog logging destinations from the running configuration.

no logging <syslog–ipv4–address> : Removes only the specified Syslog logging destination from the running configuration.

NOTE: The no logging command does not delete the Syslog server addresses stored in the startup configuration. To delete Syslog addresses in the startup configuration, you must enter the no logging command followed by the write memory command. To verify the deletion of a Syslog server address, display the startup configuration by entering the show config command.

To block the messages sent to configured Syslog servers from the currently configured debug message type, enter the no debug <debug–type> command.

To disable Syslog logging on the switch without deleting configured server addresses, enter the no debug destination logging command.

For complete information on how to configure a Syslog server and Debug/ Syslog message reports, see the Management and Configuration Guide.

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