Issue verifying md5 in c9300

[kevin2001]

Hi, we have upgraded ios in c9200 stack without issue when verifying md5 after copying image. but recently after copying image to c9300, all of them cannot show correct verifying number, Is this something wrong? Thanks

[Mark Elsen · Accepted solution]

    - Yes , that is something wrong; for starters compare the md5 sum 'in and out' of the switches ;
       Meaning on the repository where you downloaded it versus when the image is on the switch itself,

  M.

[Jens Albrecht · Accepted solution]

Hi @kevin2001,

if multiple switches do not show the expected MD5 checksum, then it is very likely that the file on your (S)FTP server is corrupt.

So you need to verify the file on your server. In case of a Windows machine you can simply use a command terminal or powershell window to verify the hash with the command "certutil -hashfile <filename> <hashalgorith>":

Example:  certutil -hashfile cat9k_iosxe.17.12.04.SPA.bin MD5

This tool can generate the MD5 and SHA512 hashes used by Cisco for software downloads among other algorithms. Other operating systems also offer such tools.

If the checksum on your server is not the correct one, then you need to re-download the software from Cisco.
It is best practice to always verify the checksum after download and/or copying to your (S)FTP server to avoid such problems.

HTH!

[kevin2001 · Accepted solution]

Very good explanation, Thanks Jens!