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infra-estrutura:cisco:ssh_nao_conecta_linux

SSH não conecta em servidores Linux

Estou tentando a partir de um roteador cisco fazer uma conexão SSH em um servidor Linux e recebo a seguinte mensagem:

hercules#ssh -l alguem 192.168.1.8
 
[Connection to 192.168.1.8 aborted: error status 0]
hercules#

Visualizando os logs do roteador

hercules#sh loggi                     
Syslog logging: enabled (0 messages dropped, 3 messages rate-limited, 0 flushes, 0 overruns, xml disabled, filtering disabled)
 
No Active Message Discriminator.
 
 
 
No Inactive Message Discriminator.
 
 
    Console logging: level debugging, 15365 messages logged, xml disabled,
                     filtering disabled
    Monitor logging: level debugging, 0 messages logged, xml disabled,
                     filtering disabled
    Buffer logging:  level warnings, 15320 messages logged, xml disabled,
                    filtering disabled
    Exception Logging: size (4096 bytes)
    Count and timestamp logging messages: disabled
    Persistent logging: disabled
 
No active filter modules.
 
    Trap logging: level informational, 15368 message lines logged
 
Log Buffer (51200 bytes):
 
015365: *Jul 31 22:23:27.573: %SSH-3-NO_MATCH: No matching cipher found: client aes128-cbc,3des-cbc,aes192-cbc,aes256-cbc server chacha20-poly1305@openssh.com,aes128-ctr,aes192-ctr,aes256-ctr,aes128-gcm@openssh.com,aes256-gcm@openssh.com
hercules#

Foi gerado um erro de não encontrar a cifra de criptografia no servidor Linux. Então vamos adicionar a cifra dentro do arquivo /etc/ssh/sshd_config

Ciphers +aes256-ctr,aes192-ctr,aes128-ctr,rijndael-cbc@lysator.liu.se,aes256-cbc,aes192-cbc,aes128-cbc,arcfour256,arcfour128,arcfour,cast128-cbc,blowfish-cbc,3des-cbc

e depois reiniciar o servidor ssh

root@megatron:~# /etc/init.d/ssh restart
[ ok ] Restarting ssh (via systemctl): ssh.service.
root@megatron:~# 

Tentar o acesso novamente.

hercules#ssh -l alguem 192.168.1.8
 
Password: 
Welcome to Ubuntu 16.04.1 LTS (GNU/Linux 4.4.0-130-generic x86_64)
 
 * Documentation:  https://help.ubuntu.com
 * Management:     https://landscape.canonical.com
 * Support:        https://ubuntu.com/advantage
 
 
Last login: Tue Jul 31 18:01:26 2018 from 192.168.1.95
alguem@megatron:~$