CDP Configuration and Verification

  • CDP is enabled by default on Cisco devices.
  • Desirable to disable CDP on a network device globally or per interface.
show cdp                # Displays CDP status
show cdp neighbors      # Shows information about CDP neighbors
show cdp neighbors detail
show cdp interface

cdp run                 # Enable CDP globally
no cdp run              # Disable CDP globally

interface <interface-id>
  no cdp enable   # Disable CDP on specific interface

LLDP Configuration and Verification

  • LLDP must be configured separately to transmit and receive LLDP packets.
lldp run
interface <interface-id>
  lldp transmit
  lldp receive
  exit

show lldp
show lldp neighbors
show lldp neighbors detail

clock Command

clock set hh:mm:ss mmm dd yyyy

clock set 20:36:00 dec 12 2015
clock timezone <timezone>
clock summer-time PDT recurring

NTP Configuration and Verification

show clock              # Displays current time on software clock
show clock detail       # Displays additionally the time source

Configure NTP Server

ntp server <ntp-server-ip>

Verify configuration

show clock detail
show ntp associations
show ip ntp associations
show ntp status

Default Logging

Enable logging

logging console         # Enables logging to console
logging buffered        # Enables logging to buffer

show logging            # Shows default logging service and messages in buffer
  • In most Cisco IOS routers, default severity level is 7, debugging.

Syslog Configuration

Three steps to configure router to send system messages to syslog server:

  1. logging <ip-address> to configure desination of syslog server.
  2. logging trap <level> to control messages that will be sent.
  3. logging source-interface <interface-id> specifies syslog packets that contain the IPv4/IPv6 address of the interface will be logged.

Example (Tftpd32 syslog server setup on 192.168.1.3):

logging 192.168.1.3
logging trap 4
logging source-interface g0/0

interface loopback 0            # Force messages via loopback
shutdown
no shutdown

Verify Syslog

Examples:

show logging | include changed state to up
show logging | begin June 12 22:35

Enable Logging Timestamps

service timestamps log datetime msec

Router File Systems

Cisco IOS File System (IFS)

show file systems
  • Current file system is indicated by preceding asterisk.
  • Pound symbol (#) is appended to the bootable disk.

Flash File System

dir

NVRAM File System

cd nvram:
pwd
dir

Backing up and Restoring TFTP

Backup:

copy running-config tftp
copy startup-config tftp

Restore:

copy tftp running-config
copy tftp startup-config

Using USB Ports on a Cisco Router

dir usbflash0:
copy running-config usbflash0:/
copy usbflash:0/<filename> running-config
more usbflash0:/<filename>

Password Recovery

  1. Enter ROMMON mode
  2. conf-reg 0x2142 to ignore startup-config
  3. Make necessary changes to original startup-config
  4. Save the new configuration
  5. config-register 0x2102 to re-enable startup-config
  6. reset

License Verification and Management

License Installation and Backup

Determine the UDI on router:

show license udi

Installing a license:

license install <stored-location-url>
reload

License verification:

show version
show license

Configure a one-time acceptance of the EULA:

license accept end user agreement

Activate an Evaluation RTU license:

license boot module <module-name> technology-package <package-name>
reload              # Required to activate software package

Technology package names for Cisco ISR G2:

  • ipbasek9
  • securityk9
  • datak9
  • uck9

Backup the license

license save <location:filename.lic>

Removing a license

To clear an active permanent license from the Cisco 1900 series, 2900 series, and 3900 series routers, perform the following steps:

Step 1. Disable the technology package active license with the command:

license boot module module-name technology-package package-name disable

Reload the router using the reload command. A reload is required to make the software package inactive.

Step 2. Clear the license from license storage:

license clear feature-name

Clear the license boot module command used for disabling the active license:

no license boot module <module-name> technology-package <package-name> disable

Note: Some licenses, such as built-in licenses, cannot be cleared. Only licenses that have been added by using the license install command are removed. Evaluation licenses are not removed.