SSH no longers works after upgrade to NX-OS 4.2.1a

[akunz2009]

We upgraded our 9509 switches from 3.3.4a to 4.2.1a and now we are unable to ssh into the switches. Any idea how to restore ssh functionality?

[Ganesh Hariharan · Accepted solution]

We upgraded our 9509 switches from 3.3.4a to 4.2.1a and now we are
unable to ssh into the switches. Any idea how to restore ssh
functionality?

Hi,

For security reasons, NX-OS Release 4.2(1a) does not support RSA version 1 keys. As a result, if you upgrade to NX-OS Release 4.2(1a) from an earlier version that did support RSA version 1 keys, and you had configured a RSA version 1 key for SSH, then you will not be able to log in through SSH following the upgrade.

Check out the belowlink from cisco regarding the same hope that helps out your query !!

http://ciscosystems.com/en/US/docs/switches/datacenter/mds9000/sw/nx-os/release/notes/19964_02.html#wp601296

If helpful do rate the post

Ganesh.H