Reset Enable password without losing config in Cisco Router

Step−by−Step Procedure
Follow these steps in order to recover your password:
Attach a terminal or PC with terminal emulation to the console port of the router.
Use these terminal settings:
♦ 9600 baud rate
♦ No parity
♦ 8 data bits
♦ 1 stop bit
♦ No flow control
Refer to these documents for information on how to cable and connect a terminal to the console port
or the AUX port:
♦ Cabling Guide for Console and AUX Ports
♦ Connecting a Terminal to the Console Port on Catalyst Switches
♦ Connect a Terminal to Catalyst 2948G−L3, 4908G−L3, and 4840G Series Switches
1.
If you can access the router, type show version at the prompt, and record the configuration register
setting. See Example of Password Recovery Procedure in order to view the output of a show version
command
Note: The configuration register is usually set to 0x2102 or 0x102. If you can no longer access the
router (because of a lost login or TACACS password), you can safely assume that your configuration
register is set to 0x2102.
2.
Use the power switch in order to turn off the router, and then turn the router back on.
Important Notes:
In order to simulate this step on a Cisco 6400, pull out and then plug in the Node Route
Processor (NRP) or Node Switch Processor (NSP) card.
♦
In order to simulate this step on a Cisco 6x00 with NI−2, pull out and then plug in the NI−2
card.
♦
3.
Press Break on the terminal keyboard within 60 seconds of power up in order to put the router into
ROMMON.
If the break sequence does not work, refer to Standard Break Key Sequence Combinations During
Password Recovery for other key combinations.
4.
Type confreg 0x2142 at the rommon 1> prompt in order to boot from Flash.
This step bypasses the startup configuration where the passwords are stored.
5.
Type reset at the rommon 2> prompt.
The router reboots, but ignores the saved configuration.
6.
7. Type no after each setup question, or press Ctrl−C in order to skip the initial setup procedure.
Type enable at the Router> prompt.
You are in enable mode and should see the Router# prompt.
8.
Type configure memory or copy startup−config running−config in order to copy the nonvolatile
RAM (NVRAM) into memory.
Important: Do not type copy running−config startup−config or write. These commands erase your
9. startup configuration.
Type show running−config.
The show running−config command shows the configuration of the router. In this configuration, the
shutdown command appears under all interfaces, which indicates all interfaces are currently shut
down. In addition, the passwords (enable password, enable secret, vty, console passwords) are in
either an encrypted or unencrypted format. You can reuse unencrypted passwords. You must change
encrypted passwords to a new password.
10.
Type configure terminal.
The hostname(config)# prompt appears.
11.
Type enable secret in order to change the enable secret password. For example:
hostname(config)#enable secret cisco
12.
Issue the no shutdown command on every interface that you use.
If you issue a show ip interface brief command in privilege EXEC mode, every interface that you
want to use should display up up. For example:
Router#show ip interface brief
13.
Type config−register . Where configuration_register_setting is
either the value you recorded in step 2 or 0x2102 . For example:
hostname(config)#config−register 0x2102
14.
Press Ctrl−z or end in order to leave the configuration mode.
The hostname# prompt appears.
15.
16. Type write memory or copy running−config startup−config in order to commit the changes

ether channel

 Create ether channel interface - interface port-channel 1

interface usage -channel-group 1 mode on



 show Commands

show etherchannel
show interfaces interface-id switchport
show interfaces interface-id trunk


show interfaces port-channel channel-number
show interfaces interface.subinterface

HSRP Topology

HSRP State Machine

HSRP is a state machine consisting of these five states:

Initial: HSRP doesn’t run. This state is seen when an interface comes up
Listen: listens for hellos, knows the virtual IP
Speak: sends hellos and participates in the election
Standby: candidate for next active router
Active: currently forwards packets sent to the virtual IP

Preempt

An HSRP router won’t attempt to become the active router when introduced to an existing topology, even if it has a higher priority. We want DSW1 to always be the Active router if it is up and the topology is stable so we need to turn on “preempt.” Preempt will cause the router to initiate an election if it has a higher priority. If priorities are equal, the router with the highest IP address will win an election.

#standby preempt

Tacacs Config

aaa new-model
aaa authentication login default group tacacs+ line
aaa authentication enable default group tacacs+ enable
aaa accounting commands 0 default start-stop group tacacs+
aaa accounting commands 15 default start-stop group tacacs+
aaa accounting connection default start-stop group tacacs+
aaa session-id common
tacacs-server host x.x.x.x
tacacs-server directed-request
tacacs-server key 7 062721025F4B0A0B0003
aaa authorization config-commands
aaa authorization exec default group tacacs+ local if-authenticated
aaa authorization commands 15 default group tacacs+ none

How to reset Cisco Router as factory default

This method uses the config-register 0x2102 command in global configuration mode.

1. Check the configuration register on the router by issuing the show version command.
   The configuration register setting is displayed in the last line of the show version command output and should be set to 0x2102. If this is not the case, enter the config-register 0x2102 command once in global configuration mode.
   

   router#configure terminal
   router(config)#config-register 0x2102
   router(config)#end
   router#

   If the show version command is issued again, the same line in the command output will have '(will be 0x2102 at next reload)' appended to the current register setting.
2. Erase the current start-up configuration on the router with the write erase command.
3. Reload the router with the reload command. When prompted to save the configuration, DO NOT save.
   

   router#reload
   System configuration has been modified. Save? [yes/no]: n
   Proceed with reload? [confirm]

   Once the router reloads, the System Configuration Dialog appears.
   

            --- System Configuration Dialog ---
   Would you like to enter the initial configuration dialog? [yes/no]:

   The router is now reset to the original factory defaults.