How To Check Flash Memory Of Cisco Switch?

Flash memory is permanent memory or non-volatile memory i.e., Data won’t be e deleted if the system is suddenly shut down or switched off due to power loss.

1. Operating system storage: The switch’s operating system is stored in flash memory, so we can update the new features easily.
2. Configuration Files: Flash memory can store the configuration files
3. Boot Sequence: At the starting stage, the switch has to load the operating system from the flash memory to the device’s memory, this is called the boot sequence.
4. File storage: Flash memory is used to store the files and images.

To check the memory you have to follow the following steps:

Step 1: First we have to set the command line interface and need to connect the switch.

• To initiate the connection with the switch we need to install the software in our systems i.e,
  • Windows (PuTTY)
  • macos/linux(Terminal)

Note: you need to have the necessary credentials for the switch to connect

Step 2: Enter Privileged EXEC Mode

• Enter privileged EXEC mode by typing the below command and provide some enabled password while prompting

 >> enable

Step 3: Now we can access global configuration mode

Step 4: Now we can check the available flash memory by typing the below command

 >> show flash

• This will display information about flash memory.

Step 5: To know the total memory and how much is free we have to type the below command:

   >> Directory of flash:/

To get the flash memory integrity we can use,

1. Backup: Use regular backups of switch’s configuration and file to another location securely, by using copy command we can copy the iOS image yo secure location.

2. Verifying Checksums: After copying image to flash , we need to verify the checksum to ensure its integrity. To check it out we need to use ‘verify‘ command followed by ‘md5’ option.

3. Secure File Transfers: While transferring files use the secured protocols such as SCP, SFTP.

4. Power Stability: Use uninterruptible power supply (UPS) to ensure power stability.

5. Keep Monitoring : Use best monitoring tools to keep the flash memory safe.

• Password protection: Better to set strong passwords and different password for access different levels;
• SSH Enabling: Enable SSH (Secure shell), it encrypts the data
• Role Based Access Control : It is used to access switch functions based on user requirements.
• Physical Security: Place the switch in locked room.
• Keep Logging And Monitoring: Keep logging to the switch and check the events regularly.
• Disabling Unused Ports: We can disable the ports that are not using.
• Access Control Lists(ACLs): Use ACLs to control the traffic from source to destination.
• Authentication: Better to use 802.1x authentication

Let’s see A few examples to understand more about this article

Example 1: Checking flash memory usage on a Cisco Catalyst switch:

• By using this command we are able to check the memory in flash , in output also we can see that available memory is displayed.

Example 2: Checking flash memory on a Cisco Nexus switch

• By using Show flash command we check the memory.
• This command show the details of amount of flash memory, amount of memory consumed, the amount of memory available, all the details are provided along with their sizes.

Example 3: Checking specific file information

• By sing `show flash: filename` command we can check the memory of particular file.
• This command can be used to show specific details of a particular file that is present in flash memory. In the place of filename you need to give your required filename.

Example 4: Checking the Free space

• By using the “show file systems” command we can check the free space
• This command will shows you about the different file systems available in the switch, It also shows the Type of the file system, the size and the usage.

Example 5: Checking the directory

• By using the “show directory” command we can check the stored directories.
• By using this command we can able to check contents that are present in flash memory, showing the files and directories stored in flash memory.
• It also provides the filenames, sizes of the files, and modification dates of the files.

In this entire article, we learnt about ways to check flash memory, how to check memory for particular file, directory, how to get integrity for flash memory, security for cisco switch and various examples related to checking flash memory.

How Can I Check Flash Memory In Cisco Switch?

By using ‘show flash’ we can able to check the flash memory

Is There Any Way To Check Memory Of A File?

Yes, by using ‘show flash:| include <filename>’

Can I Delete A File From Flash Memory?

yes, we can delete the file by using ‘delete flash : <filename>’

Is There Any To Format Flash Memory In Switch?

yes , by using the ‘format flash:’ we can check the format of flash memory

How Can I Copy File From The Network To The Flash Memory?

By using the ‘copy <source> flash’ command we can check it out.