UPGRADING EOS in the ARISTA Switches:
EOS is the Firmware for Arista Switches whereas IOS for Cisco. This blog post shows the detailed procedures to follow and to upgrade the EOS in the Arista Switches. This Post was supports for any platform or the Version you are going to upgrade in the Arista Switches.
This Post was divided into three parts :
Pre-Upgrade Process
Upgrade Process
Post-Upgrade Process
PRE-UPGRADING-PROCESS:
1 1) Check the Upgrade Path tool by clicking the below link.
and confirm it is in mlag issu compatible
2) Check if the STP agent is restartable by giving the command
NOTE: A switch can continue supporting MLAG when its peer is offline if the STP agent is restartable. When one peer is offline, data traffic flows from the devices through the MLAG component link that connects to the functioning switch.
3) Get Ready with the Console cable for Disaster recovery and confirm your able to login through console before upgrade by both tacacs on and off.
4) Before upgrading the EOS image, we will ensure that backup copies of the currently running EOS version and the running-config file are available in case of issues during the upgrade process. To copy the running-config file, use the copy running-config command. In this example, running-config is copied to a file in the flash drive on the switch.
5) Give the write command and copy both the running and startup config files
switch#copy running-config flash:/cfg_dateandtime-2019
Copy completed successfully.
Use the tftp and upload it to the local PC and also use putty and backup the run configuration.
6) Determine the size of the new EOS image. Then verify that there is enough space available on the flash drive for two copies of this image (use the dir command to check the “bytes free” figure).
NOTE: Manually download the EOS image and the configuration files including startup and running conf
switch#dir flash:
Directory of flash:/
-rwx 293168526 Nov 4 22:17 EOS4.11.0.swi
-rwx 36 Nov 8 10:24 boot-config
-rwx 37339 Jun 16 14:18 cfg_06162014
606638080 bytes total (602841088 bytes free)
7) Check the MLAG: Give the command “ show mlag” and ‘’ sh mlag config-sanity‘’ and check it is in the consistent state.
and confirm it is in mlag issu compatible
2) Check if the STP agent is restartable by giving the command
switch-1#show spanning-tree bridge detail | grep agent
Stp agent restartable : True
4) Before upgrading the EOS image, we will ensure that backup copies of the currently running EOS version and the running-config file are available in case of issues during the upgrade process. To copy the running-config file, use the copy running-config command. In this example, running-config is copied to a file in the flash drive on the switch.
5) Give the write command and copy both the running and startup config files
switch#copy running-config flash:/cfg_dateandtime-2019
Copy completed successfully.
Use the tftp and upload it to the local PC and also use putty and backup the run configuration.
6) Determine the size of the new EOS image. Then verify that there is enough space available on the flash drive for two copies of this image (use the dir command to check the “bytes free” figure).
NOTE: Manually download the EOS image and the configuration files including startup and running conf
switch#dir flash:
Directory of flash:/
-rwx 293168526 Nov 4 22:17 EOS4.11.0.swi
-rwx 36 Nov 8 10:24 boot-config
-rwx 37339 Jun 16 14:18 cfg_06162014
606638080 bytes total (602841088 bytes free)
7) Check the MLAG: Give the command “ show mlag” and ‘’ sh mlag config-sanity‘’ and check it is in the consistent state.
Note: A seamless EOS upgrade on an MLAG peer requires that the following features are configured consistently on each switch:
•VLANs
•Switchport configuration on port channel interfaces that are configured with an MLAG ID
•STP configuration (global)
UPGRADING PROCESS:
Transfer the Image File:
The target image must be copied to the file system on the switch, typically onto the flash drive. After verifying that there is space for two copies of the image, use the copy command to copy the image to the flash drive, then confirm that the new image file has been correctly transferred.
The below command shows to transfer an image file to the flash drive from various locations.
TFTP Server
Command
copy tftp://source IP and file flash:/destfile
Once the file has been transferred, verify that it is present in the directory, then confirm the MD5 checksum using the verify command. The MD5 checksum is available from the EOS download page of the Arista website.
switch#dir flash:
Directory of flash:/
-rwx 293168526 Nov 4 22:17 EOS4.20.9.swi
-rwx 36 Nov 8 10:24 boot-config
-rwx 37339 Jun 16 14:18 cfg_06162014
-rwx 394559902 May 30 02:57 EOS-4.13.1.swi
<-------OUTPUT OMITTED FROM EXAMPLE-------->
606638080 bytes total (208281186 bytes free)
switch#53#verify /md5 flash:EOS-4.21.9.swi
verify /md5 (flash:EOS-4.20.9.swi) =c277a965d0ed48534de6647b12a86991
Modify the boot-config:
After transferring and confirming the desired image file, use the boot system command to update the boot-config file to point to the new EOS image.
This command changes the boot-config file to point to the image file located in flash memory at EOS-4.20.9.swi.
switch#configure terminal
switch(config)#boot system flash:/EOS-4.21.9.swi
Use the show boot-config command to verify that the boot-config file is correct:
switch(config)#show boot-config
Software image: flash:/EOS-4.21.9.swi
Console speed: (not set)
Aboot password (encrypted):112233556kl;hjuhlhllll
Save the configuration to the startup-config file with the write command.
switch#write
reload
NOTE: Resolve all reload warnings
Note: First Perform the reload on the secondary MLAG Switch after perform the same for active MLAG Switch
POST UPGRADE PROCESS:
Verify:
After the switch finishes reloading, log into the switch and use the show version command to confirm the correct image is loaded. The Software image version line displays the version of the active image file.
By
By
G Sudhakar
Network Engineer