How to upgrade the IOS version in CISO switch/Router

Let's say we have one CISCO 2950 switch having IOS version

"c2950-i6q4l2-mz.121-22.EA4.bin"

Step 1

======

Upload the updated IOS image file on TFTP server

In our case we have upload the IOS image "c2950-i6q4l2-mz.121-22.EA8.bin" on our TFTP server.


Step 2
======

Establish the connectivity between TFTP server and your Switch.

In our case switch IP is 192.168.1.2  and TFTP server IP is 192.168.1.100


Step 3
======

Take the access of switch

switch>en
switch#copy tftp: flash:
Address or name of remote host []? 192.168.1.100
Source filename []? c2950-i6q4l2-mz.121-22.EA8.bin
Destination filename [c2950-i6q4l2-mz.121-22.EA8.bin]?

Accessing tftp://192.168.1.100/c2950-i6q4l2-mz.121-22.EA8.bin...
Loading c2950-i6q4l2-mz.121-22.EA8.bin from 192.168.1.100: !!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
[OK - 3117390 bytes]

3117390 bytes copied in 1.892 secs (1647669 bytes/sec)
Switch#


Step 4
======

Now check weather your new IOS image is uploaded in flash memory or not?

switch#sh flash
Directory of flash:/

    1  -rw-     3058048          <no date>  c2950-i6q4l2-mz.121-22.EA4.bin
    2  -rw-     3117390          <no date>  c2950-i6q4l2-mz.121-22.EA8.bin

64016384 bytes total (57840946 bytes free)
Switch#


Step 5
======

Configure switch to boot with new IPS image next time

Switch#
Switch#conf t
Enter configuration commands, one per line.  End with CNTL/Z.
Switch(config)#boot system c2950-i6q4l2-mz.121-22.EA8.bin
Switch(config)#^Z
Switch#
%SYS-5-CONFIG_I: Configured from console by console

Switch#


Step 6
======

Reboot the switch and confirm that weather switch is booting from new image or still with old image?

Switch#reload
Proceed with reload? [confirm]
%SYS-5-RELOAD: Reload requested by console. Reload Reason: Reload Command.
yC2950 Boot Loader (C2950-HBOOT-M) Version 12.1(11r)EA1, RELEASE SOFTWARE (fc1)
Compiled Mon 22-Jul-02 18:57 by miwang
Cisco WS-C2950-24 (RC32300) processor (revision C0) with 21039K bytes of memory.
2950-24 starting...
Base ethernet MAC Address: 0001.9654.2413
Xmodem file system is available.
Initializing Flash...
flashfs[0]: 2 files, 0 directories
flashfs[0]: 0 orphaned files, 0 orphaned directories
flashfs[0]: Total bytes: 64016384
flashfs[0]: Bytes used: 6175438
flashfs[0]: Bytes available: 57840946
flashfs[0]: flashfs fsck took 1 seconds.
...done Initializing Flash.

Boot Sector Filesystem (bs:) installed, fsid: 3
Parameter Block Filesystem (pb:) installed, fsid: 4


Loading "flash:/c2950-i6q4l2-mz.121-22.EA8.bin"...
########################################################################## [OK]
              Restricted Rights Legend



That's it.........