Archive for July 23, 2015

Interface IP Address Configuration

Lab Prerequisites:

  • If you’re using GNS3 than load the Stub Area Networking GNS3 topology than Router 1.
  • Establish a console session with Router 1.

Lab Objectives:

  • Configure the Primary IP Address of 10.234.51.254/24 on interface FastEthernet0/0
  • Configure a Secondary IP Address of 172.27.48.254/24 on Interface FastEthernet0/0
  • Activate the FastEthernet0/0 Interface.
  • Verify your configuration changes via the running-configuration.

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Interface Specific Configurations

Lab Prerequisites:

  • If you’re using GNS3 than load the Stub Area Networking GNS3 topology than start Router 1.
  • Establish a console session with Router 1.

Lab Objectives:

  • Statically set the speed of interface FastEthernet0/0 to 100.
  • Statically set the duplex of interface FastEthernet0/0 to Full.
  • Configure interface FastEthernet0/0 with an MTU of 1520 bytes.
  • Configure the bandwidth on interface FastEthernet0/0 to 10Mbps.
  • Configure a delay of 10ms on interface FastEthernet0/0.
  • Statically set the MAC address on interface FastEthernet0/0 to ca02.0adc.0ef9.
  • Disable Keepalives on Interface FastEthernet0/0.
  • Disable the Cisco Discovery protocol on interface FastEthernet0/0.

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Initial Configuration Dialog

Lab Prerequisites:

  • If You’re using GNS3 than load the Free CCNA Workbook GNS3 topology and start R1 than establish a console session with R1.

Lab Objectives:

  • Familiarize yourself with the Initial Configuration Dialog.

Lab Instruction:

When opening a brand new Cisco box rather it be a Cisco Switch or Router, after booting the device you’ll be prompted by the Initial Configuration Dialog. You’ll also be prompted by this dialog if you do the write erase command in privileged mode and reload the device as it erases the contents of NVRAM. When a Cisco device does not have a startup-config located in NVRAM, the device will prompt you rather or not to start the Initial Configuration Dialog.

Another reason as to why you may see this is that your configuration register is set to 0x2142 which ignores the contents of NVRAM upon boot which is commonly used for password recovery.

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Catalyst Switch Password Reset

Lab Prerequisites:

  • You’ll need an active Console session with the switch you’re unable to access.
  • You’ll need to be physically located near the switch to perform this procedure.

Lab Objectives:

  • Boot the switch into SWITCH ROM by holding the MODE button down and plugging in the power to the switch.
  • Rename the configuration file in flash to a different name such as; config.old
  • Boot the switch and copy the contents of flash:config.old into the running configuration after you’ve obtained privilege level access.
  • Copy the updated configuration to NVRAM by syncing the running config with the start-up config.

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Cisco 2600 Series Password Reset

Lab Prerequisites:

  • A Cisco 2600 Series router or greater that has an unknown console or enable password.
  • An active Serial Console session to the device that you’re unable to log into.

 

Lab Objectives:

  • Break the boot sequence when powering on the Cisco 2600 Series router to place yourself in ROM monitor mode.
  • Change the configuration register to 0x2142 to make the router bypass the contents of NVRAM when booting then reset the router.
  • (Option 1) – Once booted, place yourself into privileged mode and copy the start up-config to the running config. Afterward, you may change the line password or enable password and write the configuration by to NVRAM by issuing the copy run start command.
  • (Option 2) – Once booted, place yourself into privileged mode and do a write erase to clear the contents of the NVRAM.
  • Now change the configuration register back to 0x2102 to boot set the router to boot normally and load the NVRAM contents upon boot.
  • Now change the configuration register back to 0x2102 to boot set the router to boot normally and load the NVRAM contents upon boot.

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Cisco 2500 Series Password Reset

Lab Prerequisites:

  • A Cisco 2500 Series router that has an unknown console or enable password.
  • An active Serial Console session to the device that you’re unable to login to.

 

Lab Objectives:

  • Break the boot sequence when powering on the Cisco 2500 Series router to place yourself in rom monitor mode.
  • Change the configuration register to 0x2142 to make the router bypass the contents of NVRAM when booting then initialize the router (boot the router into IOS).
  • (Option 1) – Once booted, place yourself into privileged mode and copy the start up-config to the running config. Afterward, you may change the line password or enable password and write the configuration by to NVRAM by issuing the copy run start command.
  • (Option 2) – Once booted, place yourself into privileged mode and do a write erase to clear the contents of the NVRAM.
  • Now change the configuration register back to 0x2102 to boot set the router to boot normally and load the NVRAM contents upon boot.

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