Trouble with SSH to new 22.04 LTS VM

Mopper · December 28, 2023, 12:12am

Hello!

I’m trying to migrate an app from Ubuntu 18, so I built a new VM in ESXi with a 22.04 ISO. Once the VM is up, I’m unable to SSH in using password authentication from a windows VM (using MobaXterm) that lives on the same vlan or from another Linux 18 VM also on the same vlan. I am able to SSH to the VM from my Mac (on a different vlan).

MobaXterm on Windows and the other Linux 18 VM just keep prompting for the password, and do not provide an additional errors or messages.

Misc:

Target VM firewall is disabled
Windows / MobaXterm can SSH to other VMs without issue
Older Linux VM can SSH to other non 22.04 VMs without issue
There is no firewall between servers, pure L2, same vlan
Port 22 is open on the 22.04 VM, Mac is able to connect and Telnet is successful from the Windows / older Linux VMs

I’m guessing this is an issue with a cypher suite mismatch?

Thanks in advance!

SgtAwesomesauce · December 28, 2023, 12:15am

Are you able to use the SSH command line client and use -vvv for verbose output?

Sounds like it’s giving you an access denied error. Are you trying to ssh to the root user? Ubuntu has restrictions on the root user for SSH, so it’s either disabled entirely or you’ll need to use an SSH key.

Mopper · December 28, 2023, 12:19am

I have!

ssh -vvv ssh_user@<Dest_IP>
OpenSSH_9.4p1, OpenSSL 3.0.11 19 Sep 2023
debug1: Reading configuration data /etc/ssh_config
debug1: /etc/ssh_config line 10: Deprecated option "useroaming"
debug2: resolve_canonicalize: hostname <Dest_IP> is address
debug3: expanded UserKnownHostsFile '~/.ssh/known_hosts' -> '/home/User/.ssh/known_hosts'
debug3: expanded UserKnownHostsFile '~/.ssh/known_hosts2' -> '/home/User/.ssh/known_hosts2'
debug3: ssh_connect_direct: entering
debug1: Connecting to <Dest_IP> [<Dest_IP>] port 22.
debug3: set_sock_tos: set socket 4 IP_TOS 0x48
debug1: Connection established.
debug1: identity file /home/User/.ssh/id_rsa type -1
debug1: identity file /home/User/.ssh/id_rsa-cert type -1
debug1: identity file /home/User/.ssh/id_ecdsa type -1
debug1: identity file /home/User/.ssh/id_ecdsa-cert type -1
debug1: identity file /home/User/.ssh/id_ecdsa_sk type -1
debug1: identity file /home/User/.ssh/id_ecdsa_sk-cert type -1
debug1: identity file /home/User/.ssh/id_ed25519 type -1
debug1: identity file /home/User/.ssh/id_ed25519-cert type -1
debug1: identity file /home/User/.ssh/id_ed25519_sk type -1
debug1: identity file /home/User/.ssh/id_ed25519_sk-cert type -1
debug1: identity file /home/User/.ssh/id_xmss type -1
debug1: identity file /home/User/.ssh/id_xmss-cert type -1
debug1: identity file /home/User/.ssh/id_dsa type -1
debug1: identity file /home/User/.ssh/id_dsa-cert type -1
debug1: Local version string SSH-2.0-OpenSSH_9.4
debug1: Remote protocol version 2.0, remote software version OpenSSH_8.2p1 Ubuntu-4ubuntu0.10
debug1: compat_banner: match: OpenSSH_8.2p1 Ubuntu-4ubuntu0.10 pat OpenSSH* compat 0x04000000
debug2: fd 4 setting O_NONBLOCK
debug1: Authenticating to <Dest_IP>:22 as 'ssh_user'
debug3: record_hostkey: found key type ED25519 in file /home/User/.ssh/known_hosts:16
debug3: load_hostkeys_file: loaded 1 keys from <Dest_IP>
debug1: load_hostkeys: fopen /home/User/.ssh/known_hosts2: No such file or direcssh_usery
debug1: load_hostkeys: fopen /etc/ssh_known_hosts: No such file or direcssh_usery
debug1: load_hostkeys: fopen /etc/ssh_known_hosts2: No such file or direcssh_usery
debug3: order_hostkeyalgs: have matching best-preference key type [email protected], using HostkeyAlgorithms verbatim
debug3: send packet: type 20
debug1: SSH2_MSG_KEXINIT sent
debug3: receive packet: type 20
debug1: SSH2_MSG_KEXINIT received
debug2: local client KEXINIT proposal
debug2: KEX algorithms: [email protected],curve25519-sha256,[email protected],ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,diffie-hellman-group14-sha256,ext-info-c
debug2: host key algorithms: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],ssh-ed25519,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,[email protected],[email protected],rsa-sha2-512,rsa-sha2-256
debug2: ciphers ctos: [email protected],aes128-ctr,aes192-ctr,aes256-ctr,[email protected],[email protected]
debug2: ciphers stoc: [email protected],aes128-ctr,aes192-ctr,aes256-ctr,[email protected],[email protected]
debug2: MACs ctos: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: MACs stoc: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: compression ctos: [email protected],zlib,none
debug2: compression stoc: [email protected],zlib,none
debug2: languages ctos:
debug2: languages stoc:
debug2: first_kex_follows 0
debug2: reserved 0
debug2: peer server KEXINIT proposal
debug2: KEX algorithms: curve25519-sha256,[email protected],ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,diffie-hellman-group14-sha256,[email protected]
debug2: host key algorithms: rsa-sha2-512,rsa-sha2-256,ssh-rsa,ecdsa-sha2-nistp256,ssh-ed25519
debug2: ciphers ctos: [email protected],aes128-ctr,aes192-ctr,aes256-ctr,[email protected],[email protected]
debug2: ciphers stoc: [email protected],aes128-ctr,aes192-ctr,aes256-ctr,[email protected],[email protected]
debug2: MACs ctos: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: MACs stoc: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: compression ctos: none,[email protected]
debug2: compression stoc: none,[email protected]
debug2: languages ctos:
debug2: languages stoc:
debug2: first_kex_follows 0
debug2: reserved 0
debug1: kex: algorithm: curve25519-sha256
debug1: kex: host key algorithm: ssh-ed25519
debug1: kex: server->client cipher: [email protected] MAC: <implicit> compression: [email protected]
debug1: kex: client->server cipher: [email protected] MAC: <implicit> compression: [email protected]
debug3: send packet: type 30
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug3: receive packet: type 31
debug1: SSH2_MSG_KEX_ECDH_REPLY received
debug1: Server host key: ssh-ed25519 SHA256:6p3CxLFqRb1hpiHlA8t+T6IIhxyEmWXxEhx0MoEOrz0
debug3: record_hostkey: found key type ED25519 in file /home/User/.ssh/known_hosts:16
debug3: load_hostkeys_file: loaded 1 keys from <Dest_IP>
debug1: load_hostkeys: fopen /home/User/.ssh/known_hosts2: No such file or direcssh_usery
debug1: load_hostkeys: fopen /etc/ssh_known_hosts: No such file or direcssh_usery
debug1: load_hostkeys: fopen /etc/ssh_known_hosts2: No such file or direcssh_usery
debug1: Host '<Dest_IP>' is known and matches the ED25519 host key.
debug1: Found key in /home/User/.ssh/known_hosts:16
debug3: send packet: type 21
debug2: ssh_set_newkeys: mode 1
debug1: rekey out after 134217728 blocks
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug3: receive packet: type 21
debug1: SSH2_MSG_NEWKEYS received
debug2: ssh_set_newkeys: mode 0
debug1: rekey in after 134217728 blocks
debug3: ssh_get_authentication_socket_path: path '/tmp/ssh-vCq1W20aUQj7/agent.1427'
debug1: get_agent_identities: bound agent to hostkey
debug1: get_agent_identities: ssh_fetch_identitylist: agent contains no identities
debug1: Will attempt key: /home/User/.ssh/id_rsa
debug1: Will attempt key: /home/User/.ssh/id_ecdsa
debug1: Will attempt key: /home/User/.ssh/id_ecdsa_sk
debug1: Will attempt key: /home/User/.ssh/id_ed25519
debug1: Will attempt key: /home/User/.ssh/id_ed25519_sk
debug1: Will attempt key: /home/User/.ssh/id_xmss
debug1: Will attempt key: /home/User/.ssh/id_dsa
debug2: pubkey_prepare: done
debug3: send packet: type 5
debug3: receive packet: type 7
debug1: SSH2_MSG_EXT_INFO received
debug1: kex_input_ext_info: server-sig-algs=<ssh-ed25519,[email protected],ssh-rsa,rsa-sha2-256,rsa-sha2-512,ssh-dss,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,[email protected]>
debug3: receive packet: type 6
debug2: service_accept: ssh-userauth
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug3: send packet: type 50
debug3: receive packet: type 51
debug1: Authentications that can continue: publickey,password
debug3: start over, passed a different list publickey,password
debug3: preferred hostbased,publickey,password,keyboard-interactive
debug3: authmethod_lookup publickey
debug3: remaining preferred: password,keyboard-interactive
debug3: authmethod_is_enabled publickey
debug1: Next authentication method: publickey
debug1: Trying private key: /home/User/.ssh/id_rsa
debug3: no such identity: /home/User/.ssh/id_rsa: No such file or direcssh_usery
debug1: Trying private key: /home/User/.ssh/id_ecdsa
debug3: no such identity: /home/User/.ssh/id_ecdsa: No such file or direcssh_usery
debug1: Trying private key: /home/User/.ssh/id_ecdsa_sk
debug3: no such identity: /home/User/.ssh/id_ecdsa_sk: No such file or direcssh_usery
debug1: Trying private key: /home/User/.ssh/id_ed25519
debug3: no such identity: /home/User/.ssh/id_ed25519: No such file or direcssh_usery
debug1: Trying private key: /home/User/.ssh/id_ed25519_sk
debug3: no such identity: /home/User/.ssh/id_ed25519_sk: No such file or direcssh_usery
debug1: Trying private key: /home/User/.ssh/id_xmss
debug3: no such identity: /home/User/.ssh/id_xmss: No such file or direcssh_usery
debug1: Trying private key: /home/User/.ssh/id_dsa
debug3: no such identity: /home/User/.ssh/id_dsa: No such file or direcssh_usery
debug2: we did not send a packet, disable method
debug3: authmethod_lookup password
debug3: remaining preferred: keyboard-interactive
debug3: authmethod_is_enabled password
debug1: Next authentication method: password

Mopper · December 28, 2023, 12:20am

Are you trying to ssh to the root user? Ubuntu has restrictions on the root user for SSH, so it’s either disabled entirely or you’ll need to use an SSH key.

That could be, but then it wouldn’t let me login from my Mac, right?

Mopper · December 28, 2023, 7:01pm

This ended up being an ip conflict.
Thanks!