Instant On - Wired

Hi,

I'm attempting to use Config backup using SCP from my 1830 24P ( running version 2.9.1 firmware).  

My SCP server is running Debian 12 Bookworm ( amd64).

I get this error on the 1830 Web Interface:

On the Debian server, I get the following errors:

: Unable to negotiate with 10.0.0.12 port 50050: no matching key exchange method found. Their offer: diffie-hellman-group-exchange-sha1,diffie-hellman-group1-sha1,diffie-hellman-group14-sha1 [preauth]

: Unable to negotiate with 10.0.0.12 port 50051: no matching key exchange method found. Their offer: diffie-hellman-group-exchange-sha1,diffie-hellman-group1-sha1,diffie-hellman-group14-sha1 [preauth]

: Unable to negotiate with 10.0.0.12 port 50052: no matching key exchange method found. Their offer: diffie-hellman-group-exchange-sha1,diffie-hellman-group1-sha1,diffie-hellman-group14-sha1 [preauth]

Is there any way to tell the 1830 to use any newer algorithms such as those listed on ssh key-exchange-algorithms ? 

Thanks again,

Travis

Update 1: I found a "temporary" "workaround" to allow use of old ciphers / keys on Debian 12.

The workaround allows the backup to occur ; so I'm happy :) 

In "/etc/ssh/sshd_config" :

# uncomment the following lines:

HostKey /etc/ssh/ssh_host_rsa_key
HostKey /etc/ssh/ssh_host_ecdsa_key
HostKey /etc/ssh/ssh_host_ed25519_key

# add end of the file add:

KexAlgorithms diffie-hellman-group1-sha1,curve25519-sha256@libssh.org,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group14-sha1 
Ciphers +aes128-cbc
HostKeyAlgorithms ssh-rsa,ssh-dss
PubkeyAcceptedKeyTypes ssh-rsa,ssh-dss

# ----
# save the file and restart ssh server with:
sudo systemctl restart ssh

Result:

SCP backup works!

------------------------------
Travis Thorne
------------------------------