SSH connection to Cisco switch automatically closed by switch after successful connection

[TheOtherGuy]

I am connecting to the Cisco Catalyst switch via a proxy server. The connection works, but the SSH connection is disconnected shortly by the switch: DEBUG -- : 10.0.1.4 raised Net::SSH::Disconnect with msg "connection closed by remote host".

I can connect to the Cisco switch from the Oxidized Docker container via the proxy server.

There appears to be no issue with SSH key negotiation.

I am using the latest version of Oxidized, version 0.32.

Below is the Oxidized log:

I, [2025-02-19T08:10:10.020837 #33]  INFO -- : Oxidized starting, running as pid 33
I, [2025-02-19T08:10:10.023213 #33]  INFO -- : lib/oxidized/nodes.rb: Loading nodes
D, [2025-02-19T08:10:10.023376 #33] DEBUG -- : resolving DNS for CriSW...
D, [2025-02-19T08:10:10.023401 #33] DEBUG -- : IPADDR 10.0.1.4
D, [2025-02-19T08:10:10.023471 #33] DEBUG -- : node.rb: resolving node key 'model', with passed global value of '' and node value 'ios'
D, [2025-02-19T08:10:10.023489 #33] DEBUG -- : node.rb: setting node key 'model' to value 'ios' from node
D, [2025-02-19T08:10:10.023520 #33] DEBUG -- : lib/oxidized/node.rb: Loading model "ios"
D, [2025-02-19T08:10:10.028624 #33] DEBUG -- : lib/oxidized/model/model.rb Added all to the commands list
D, [2025-02-19T08:10:10.028659 #33] DEBUG -- : lib/oxidized/model/model.rb Added secret to the commands list
D, [2025-02-19T08:10:10.028676 #33] DEBUG -- : lib/oxidized/model/model.rb Added show version to the commands list
D, [2025-02-19T08:10:10.028689 #33] DEBUG -- : lib/oxidized/model/model.rb Added show vtp status to the commands list
D, [2025-02-19T08:10:10.028700 #33] DEBUG -- : lib/oxidized/model/model.rb Added show inventory to the commands list
D, [2025-02-19T08:10:10.028879 #33] DEBUG -- : node.rb: resolving node key 'input', with passed global value of 'ssh' and node value ''
D, [2025-02-19T08:10:10.028906 #33] DEBUG -- : node.rb: setting node key 'input' to value 'ssh' from passed global value
D, [2025-02-19T08:10:10.489082 #33] DEBUG -- : node.rb: resolving node key 'output', with passed global value of 'git' and node value ''

D, [2025-02-19T08:10:10.489141 #33] DEBUG -- : node.rb: setting node key 'output' to value 'git' from passed global value
D, [2025-02-19T08:10:10.661121 #33] DEBUG -- : node.rb: resolving node key 'username', with passed global value of '' and node value 'ox
idized'
D, [2025-02-19T08:10:10.661197 #33] DEBUG -- : node.rb: setting node key 'username' to value 'oxidized' from node
D, [2025-02-19T08:10:10.661216 #33] DEBUG -- : node.rb: resolving node key 'password', with passed global value of '' and node value 'Ap
ple123#'
D, [2025-02-19T08:10:10.661227 #33] DEBUG -- : node.rb: setting node key 'password' to value 'passwordx' from node
I, [2025-02-19T08:10:10.661379 #33]  INFO -- : lib/oxidized/nodes.rb: Loaded 1 nodes
D, [2025-02-19T08:10:11.658620 #33] DEBUG -- : lib/oxidized/core.rb: Starting the worker...
D, [2025-02-19T08:10:11.662647 #33] DEBUG -- : lib/oxidized/worker.rb: Jobs running: 0 of 1 - ended: 0 of 1
D, [2025-02-19T08:10:11.671745 #33] DEBUG -- : lib/oxidized/worker.rb: Added /CriSW to the job queue
D, [2025-02-19T08:10:11.671814 #33] DEBUG -- : lib/oxidized/worker.rb: 1 jobs running in parallel
D, [2025-02-19T08:10:11.672467 #33] DEBUG -- : lib/oxidized/job.rb: Starting fetching process for CriSW at 2025-02-19 08:10:11 U
TC
D, [2025-02-19T08:10:11.673054 #33] DEBUG -- : lib/oxidized/input/ssh.rb: I/O Debuging to /home/oxidized/.config/oxidized/logs/10.0.1.4-ssh
D, [2025-02-19T08:10:11.673125 #33] DEBUG -- : lib/oxidized/input/ssh.rb: Connecting to CriSW
D, [2025-02-19T08:10:11.675930 #33] DEBUG -- : AUTH METHODS::["publickey", "keyboard-interactive", "password","none"]
D, [2025-02-19T08:10:11.692200 #33] DEBUG -- net.ssh.transport.session[7a8]: establishing connection to 10.0.1.4:22 through proxy
D, [2025-02-19T08:10:11.895542 #33] DEBUG -- net.ssh.transport.session[7a8]: connection established
I, [2025-02-19T08:10:11.895663 #33]  INFO -- net.ssh.transport.server_version[7e4]: negotiating protocol version
D, [2025-02-19T08:10:11.895685 #33] DEBUG -- net.ssh.transport.server_version[7e4]: local is `SSH-2.0-Ruby/Net::SSH_7.3.0 x86_64-linux-gnu'
D, [2025-02-19T08:10:11.895742 #33] DEBUG -- net.ssh.transport.server_version[7e4]: remote is `SSH-2.0-Cisco-1.25'
I, [2025-02-19T08:10:11.896293 #33]  INFO -- net.ssh.transport.algorithms[7f8]: sending KEXINIT
D, [2025-02-19T08:10:11.896451 #33] DEBUG -- io[80c]: queueing packet nr 0 type 20 len 1572
D, [2025-02-19T08:10:11.896491 #33] DEBUG -- io[80c]: sent 1576 bytes
D, [2025-02-19T08:10:11.899927 #33] DEBUG -- io[80c]: read 248 bytes
D, [2025-02-19T08:10:11.900078 #33] DEBUG -- io[80c]: received packet nr 0 type 20 len 244
I, [2025-02-19T08:10:11.900135 #33]  INFO -- net.ssh.transport.algorithms[7f8]: got KEXINIT from server
I, [2025-02-19T08:10:11.900198 #33]  INFO -- net.ssh.transport.algorithms[7f8]: negotiating algorithms
D, [2025-02-19T08:10:11.900310 #33] DEBUG -- net.ssh.transport.algorithms[7f8]: negotiated:
* kex: ecdh-sha2-nistp521
* host_key: ssh-rsa
* encryption_server: aes256-ctr
* encryption_client: aes256-ctr
* hmac_client: hmac-sha2-512
* hmac_server: hmac-sha2-512
* compression_client: none
* compression_server: none
* language_client:
* language_server:
D, [2025-02-19T08:10:11.900344 #33] DEBUG -- net.ssh.transport.algorithms[7f8]: exchanging keys
D, [2025-02-19T08:10:11.900947 #33] DEBUG -- io[80c]: queueing packet nr 1 type 30 len 148
D, [2025-02-19T08:10:11.901002 #33] DEBUG -- io[80c]: sent 152 bytes
D, [2025-02-19T08:10:12.548698 #33] DEBUG -- io[80c]: read 804 bytes
D, [2025-02-19T08:10:12.590490 #33] DEBUG -- io[80c]: read 436 bytes
D, [2025-02-19T08:10:12.590675 #33] DEBUG -- io[80c]: received packet nr 1 type 31 len 1220
D, [2025-02-19T08:10:12.593811 #33] DEBUG -- io[80c]: queueing packet nr 2 type 21 len 20
D, [2025-02-19T08:10:12.593888 #33] DEBUG -- io[80c]: sent 24 bytes
D, [2025-02-19T08:10:12.593960 #33] DEBUG -- io[80c]: received packet nr 2 type 21 len 12
D, [2025-02-19T08:10:12.594417 #33] DEBUG -- net.ssh.authentication.session[820]: beginning authentication of `oxidized'
D, [2025-02-19T08:10:12.594662 #33] DEBUG -- io[80c]: queueing packet nr 3 type 5 len 28
D, [2025-02-19T08:10:12.594711 #33] DEBUG -- io[80c]: sent 96 bytes
D, [2025-02-19T08:10:12.597807 #33] DEBUG -- io[80c]: read 96 bytes
D, [2025-02-19T08:10:12.597966 #33] DEBUG -- io[80c]: received packet nr 3 type 6 len 28
D, [2025-02-19T08:10:12.598062 #33] DEBUG -- net.ssh.authentication.session[820]: trying publickey
D, [2025-02-19T08:10:12.598427 #33] DEBUG -- net.ssh.authentication.agent[834]: connecting to ssh-agent
E, [2025-02-19T08:10:12.598518 #33] ERROR -- net.ssh.authentication.agent[834]: could not connect to ssh-agent: Agent not configured
D, [2025-02-19T08:10:12.598644 #33] DEBUG -- net.ssh.authentication.methods.publickey[85c]: trying publickey (03:56:h6:44:67:4h:aa:e1:a2
:91:1e:22:25:c9:g7:82) alg rsa-sha2-256
D, [2025-02-19T08:10:12.598830 #33] DEBUG -- io[80c]: queueing packet nr 4 type 50 len 364
D, [2025-02-19T08:10:12.598884 #33] DEBUG -- io[80c]: sent 432 bytes
D, [2025-02-19T08:10:12.600000 #33] DEBUG -- io[80c]: read 368 bytes
D, [2025-02-19T08:10:12.600118 #33] DEBUG -- io[80c]: received packet nr 4 type 53 len 300
I, [2025-02-19T08:10:12.600171 #33]  INFO -- net.ssh.authentication.session[820]: C
***************************************Info**********************************************

D, [2025-02-19T08:10:12.673016 #33] DEBUG -- : lib/oxidized/worker.rb: 1 jobs running in parallel
D, [2025-02-19T08:10:12.705310 #33] DEBUG -- : 10.0.1.4 raised Net::SSH::Disconnect with msg "connection closed by remote host"
D, [2025-02-19T08:10:12.705411 #33] DEBUG -- : lib/oxidized/node.rb: Oxidized::SSH failed for CriSW