ASA upgrade and SSH

jjoseph01 · ‎09-29-2008

Hi all. I just upgraded an ASA5505 that I had SSH access to, from the outside interface. I just did a IOS upgrade on it to 8.0 and how I cant SSH into it anymore. I can vpn in, but cant SSH. Does it change something when an upgrade is done so that you have to redo the SSH portion again?

Matthew Warrick · ‎09-30-2008

Assuming you have the proper access-list in place I'd re-generate the SSH key pair and check the version of SSH your client software is using, i.e. 1 or 2, and make sure your encryption threshold isn't set higher than your firewall license supports, i.e. firewall only has a 3DES license and your client software is trying to force AES.

cisco24x7 · ‎09-30-2008

"i.e. firewall only has a 3DES license and your client software is trying to force AES"

Most ssh client software are very smart these

days. SecureCRT, putty or Linux ssh clients,

have sequences to force from the highest to

the lowest, or whatever you set it to be:

debug2: kex_parse_kexinit: aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour,aes192-cbc,aes256-cbc,rijndael-cbc@lysator.liu.se

jjoseph01 · ‎09-30-2008

Yeah, Im pretty sure its not my ssh client trying to force AES. As I stated earlier, I was able to SSH in before the upgrade.

With that said, I am now able to get to the ASA via SSH. Not sure what happened, but a little while later, I was able to get into it without issue. Again, I dont know exactly what happened, but its working again. Thanks.