PipRouting.Net: Miscellaneous: Tips and Tricks that come in very handy

To load an IOS onto a router using rommon mode via Ethernet cable:

Start the TFTP server

· Create a folder and copy the IOS to the folder

· Specify the correct path in the TFTP software

Connect to the router via a crossover Ethernet cable
Verify you have enough space for the IOS you will be loading

· You can load more than one IOS file as long as you have enough memory. You can boot the desired IOS by typing: boot system flash iosversion-mz.124-15.T7.bin

At the rommon prompt enter the following commands

· IOS commands are case sensitive, and the use of the directional arrows and tab key do not work in this mode.

IP_ADDRESS= 192.168.1.1
IP_SUBNET_MASK= 255.255.255.0
DEFAULT_GATEWAY=192.168.1.1
TFTP_SERVER= 192.168.1.2 à this is the computer with the tftp client and IOS software

TFTP_FILE= iosversion-mz.124-15.T7.bin
tftpdnld à Start the tftp load process.

The router will then issue a warning message:

Invoke this command for disaster recovery only.
WARNING: all existing data in all partitions on flash will be lost!
Do you wish to continue? y/n: [n]: y

Enter y, and the IOS will load
Once loaded you must boot up the new IOS by issuing the boot command

*********************************************************************************************************

Private Address Space: 
   The Internet Assigned Numbers Authority (IANA) has reserved the
   following three blocks of the IP address space for private internets:

     10.0.0.0        -   10.255.255.255  (10/8 prefix)
     172.16.0.0      -   172.31.255.255  (172.16/12 prefix)
     192.168.0.0     -   192.168.255.255 (192.168/16 prefix)

Reference: http://www.faqs.org/rfcs/rfc1918.html
*******************************************************************************************

The Supervisor Engines available for the Cisco Catalyst 4000 and 4500 Series Switches are positioned as such:

Supervisor Engine I Deployed in the Cisco Catalyst 4003 Switch only
Supervisor Engine II Deployed in the Cisco Catalyst 4006, 4503, or 4506 Switches for entry-level, and only Layer 2 switching with support for Cisco CatOS. For new opportunities, position the new Supervisor Engine II-Plus whenever possible.
Note: Supervisor I and Supervisor II only supports CatOS system software. In order to have Layer 3 functionality in these switches, you can install Catalyst 4000 Layer 3 Services Module (WS-X4232-L3).
Supervisor Engine II-Plus Deployed in the Cisco Catalyst 4006, 4503, 4506, or 4507R Switches for entry-level, Layer 2 switching with basic Layer 3 services. Optimized for small and medium-sized enterprises and education customers.
Note: Supervisor II-Plus (Sup2+). Sup-III, Sup-IV and Sup-V only support Cisco IOS system software.
Supervisor Engine III Supervisor Engine II-Plus delivers non-blocking Layer 2 switching with Layer 3/4 intelligent services to power resilient, multilayer switching solutions for converged data, voice, and video networks.
Supervisor Engine IV Deployed in the Cisco Catalyst 4006, 4503, 4506, or 4507R Switches for highly scalable Layer 2, 3, and 4 switching with advanced Layer 3 and 4 services for deployment flexibility and investment protection.
For all new opportunities, position the Supervisor Engine IV whenever possible. It delivers everything that the Supervisor Engine III offers plus redundancy, a NetFlow Services Card option, and dynamic buffer limiting, at a better price point.
Supervisor Engine V An extension of the Supervisor Engine IV that offers higher capacity, nonblocking Cisco Layer 2-4 switching at 96 Gbps, with performance of 72 Mpps
Supervisor Engine V-10GE The Cisco Catalyst 4500 Series Supervisor Engine V-10GE offers non-blocking, Layer 2 4 switching with wire-speed 10-Gigabit Ethernet uplinks, that increases the Catalyst 4500 Series overall performance to 136-Gbps capacity and 102-mpps throughput.

When you run CatOS, then you see the (enable) prompt, and in Cisco IOS , you see > and # prompt.

reference: https://supportforums.cisco.com/docs/DOC-4533#cf

CatOS boot failure recovery

When a switche loads it runs the software from RAM, after the switch loads the software image from a Flash device. If flash images get corrupted or deleted, the switch cannot boot properly. In this condition, the switch generally falls back into a ROM monitor (ROMmon) mode, which has limited feature capability. Rommon mode is not what you want to see when you reload a switch, this usually means there is a serious error some where/some how. Fear not, you should become familiar with Rommon mode, it will come in handy when you are in a data closet at 3AM in the morning. So here we go... this particular post is a combination of my experiences so far along with Cisco's documentation.

delete: you can issue the delete command to delete unwanted images from flash/bootflash.

squeeze: after an image is deleted you might still see it in flash, issue the squeeze command to clean up

deleted files.

undelete: you can issue the undelete command to recover deleted images as long as you have not reloaded the switch or issued the squeeze command. This is applicable to Catalyst 4500/4000, 5500/5000, and 6500/6000 series switches.

Verify that all the variables are set and that you are able to reach the TFTP server.

rommon 1> show interface
me1: inet 172.20.58.227 netmask 255.255.255.0 broadcast 172.20.58.255

!--- If you do not see an IP address on the ME1 interface, 
!--- issue this command in order to set the IP address:
!--- set interface me1  [netmask]
!--- An example is set interface me1 172.20.58.227 255.255.255.0.
rommon 2> show ip route
Destination             Gateway                 Interface
----------------------- ----------------------- ---------
default                 0.0.0.0                 me1

In this example, there is no default gateway set. If the TFTP server is not on the same network, you need to set a default route.

Set the default gateway, if necessary.

rommon 3> set ip route default 172.20.58.1

The command gives no response, but you can issue the show ip route command again for verification.

rommon 4> show ip route     
Destination             Gateway                 Interface
----------------------- ----------------------- ---------
 default                 172.20.58.1             me1

Check that the TFTP server variable is correctly set.
If you issue the set command by itself, the command displays the environment variables.

rommon 5> set
PS1=rommon ! >
AutobootStatus=success
MemorySize=32
DiagBootMode=post
?=0
ROMVERSION=4.4(1)
WHICHBOOT=bootflash:cat4000.4-4-1.bin
BOOT=bootflash:cat4000.4-4-1.bin,1;

Because the TFTP server variable is not part of the environment here, you must set the variable before you can proceed. Set the variable, verify that it is actually in the environment, and then ping the server in order to validate connectivity. You do not need to have the TFTP server environment variable set in order to be able to ping the server. You must access the file on the server with use of the boot command, which Step 4 shows.

rommon 6> tftpserver=172.20.59.67 

!--- This command sets the TFTP server variable.
rommon 7> set 

!--- This command verifies the setting.
PS1=rommon ! >
AutobootStatus=success
MemorySize=32
DiagBootMode=post
Tftpserver=172.20.59.67
?=0
ROMVERSION=4.4(1)
WHICHBOOT=bootflash:cat4000.4-4-1.bin
BOOT=bootflash:cat4000.4-4-1.bin,1;

Boot the system from the network (TFTP) server.

rommon 9> boot cat4000.4-4-1.bin

After you boot the system, you get the switch console.

When the system is fully operational again, issue the copy tftp flash command in order to copy the valid image to the Flash.

reference:
http://www.cisco.com/en/US/products/hw/switches/ps663/products_tech_note09186a00800949c3.shtml
**********************************************************************************************

Recover Switch password

Hold down the mode button located on the left side of the front panel, while you reconnect the power cable to the switch.

When the switch reloads you will see the following:

*** The system will autoboot in 15 seconds ***
Send break character to prevent autobooting. press ctrl + break

3. Issue the flash_init command.

4. Issue the load_helper command note: some switches might not have this file, you can issue

the ? at the switch: prompt.

5. Issue dir flash: the file we are interested in is the "config.text" this is where the password

is kept.

6. Type rename flash:config.text flash:config.old to rename the configuration file.

7. Type boot to reload the switch.

When the switch reloads you will be at the initial config dialog box...

I hope this helps, it saved me a lot of headaches.

********************************************************************

Cisco Supervisor Comparison

http://www.cisco.com/en/US/products/hw/switches/ps4324/prod_models_comparison.html

********************************************************************

Set boot file image

CatOS

Console> (enable) SET boot ?
  auto-config                Set auto config file
  config-register            Set configuration register
  sync                       Set sync parameters
  system                     Set BOOT environment variable
Console> (enable) SET boot config-register ?
  auto-config                Set auto config recurring
  baud                       Set Baud rate
  boot                       Set boot mode
  ignore-config              Enable/disable ignoring config
                      Hexadecimal value
Console> (enable) SET boot config-register boot ?
  bootflash                  Set boot bootflash
  rommon                     Set boot rommon
  system                     Set boot bootflash
Console> (enable) SET boot config-register boot bootflash ?
                        Module number
  
Console> (enable) SET boot config-register boot bootflash 0X2102

 **************************************************************

Show contents of Bootflash

Console> (enable) SH BOOTflash:
Unknown command "show BOOTflash:".  Use 'show help' for more info.
Console> (enable) sh boot
BOOT variable = bootflash:cat4000-k8.8-3-2-GLX.bin,1;
CONFIG_FILE variable = bootflash:switch.cfg

Configuration register is 0x2
ignore-config: disabled
auto-config: non-recurring
console baud: 9600
boot: image specified by the boot system commands
***************************************************************

Show which image loaded

Console> (enable) whichboot
Boot image name is 'bootflash:cat4000-k8.8-3-2-GLX.bin'.
Console> (enable)

***************************************************************

Console> (enable) sh boot 1
BOOT variable = bootflash:cat4000-k8.8-3-2-GLX.bin,1;
CONFIG_FILE variable = bootflash:switch.cfg

Configuration register is 0x2
ignore-config: disabled
auto-config: non-recurring
console baud: 9600
boot: image specified by the boot system commands
***************************************************************

Console> (enable) set boot system flash bootflash:cat4000-k8.8-3-2-GLX.bin

***************************************************************

Configure IP Address

Console> (enable) set interface ?
  me1                        Set me1 interface
  sc0                        Set sc0 interface
  sl0                        Set sl0 interface
  trap                       Set interface trap
Console> (enable) set interface sc0 ?
  dhcp                       Set dhcp interface
  down                       Shut down the interface
  up                         Bring up the interface
                    ip_addr/netmask or ip_addr/maskbit
                    IP address
                       VLAN number
Console> (enable) set interface sc0 1.1.1.1 ?
                     IP subnet mask (must be in dot format)
  
Console> (enable) set interface sc0 1.1.1.1 255.0.0.0 ?
                    Broadcast interface IP address
  
Console> (enable) set interface sc0 1.1.1.1 255.0.0.0
******************************************************************

Set CatOS default gateway

Console> (enable) set ip ?
  alias                      Set alias for IP Address
  dns                        Set DNS information
  fragmentation              Set IP fragmentation enable/disable
  http                       Set IP HTTP server information
  permit                     Set IP Permit List
  redirect                   Set ICMP redirect enable/disable
  route                      Set IP routing table entry
  unreachable                Set ICMP unreachable messages
Console> (enable) set ip route ?
  default                    Set default route
                IP address or hostname
        ip_addr or ip_addr/netmask or ip_addr/maskbit
Console> (enable) set ip route default ?
                    IP address
Console> (enable) set ip route default 1.1.1.1 ?
  primary                    Specify as primary
  
Console> (enable) set ip route default 1.1.1.1 primary ?
  
Console> (enable) set ip route default 1.1.1.1 primary

________________________________________________________________

Recover from CatOS  boot failure

Problem: You accidentally deleted your IOS or it got corrupted

Solution:

Plug an ethernet cable from your machine into the management interface of the sup

2. Set an IP Address to the management interface

Set interface me1 192.1681.1.1 255.255.255.0

3.Set the IP Address of the TFTP server

```
TftpServer=192.168.1.2 
```

4. Type set to verify the boot options. Verify the IP Address of the TFTP server

5. Type boot imagename.bin

PipRouting.Net

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Miscellaneous: Tips and Tricks that come in very handy

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