expected key exchange group packet from server

[JohanHendrikx]

For no reseason Ive got this error when I want to connect to one of mine switches with ssh with putty from my PC.
A ssh session to another switch works fine.

from an other switch I can do a ssh session to the same switch .

Ive cleared the putty cache already.

What can I do to fix this?

[Gareth_Mitchell]

Hi

You could try to change the ordering of KEX in the SSH config section of putty, move Diffie-Hellman group exchange from the top of the list, try with Diffie-Hellman group 14.

If that doesn't help, open a case with the details of the switch that doesn't work including the OS version and the version of putty you have.

-Gareth