Error appears in Plesk SSH Terminal extension: ssh_exchange_identification: read: Connection reset by peer

Symptoms

• Error appears in Plesk SSH Terminal extension:
  

  PLESK_ERROR: ssh_exchange_identification: read: Connection reset by peer

  
• In/var/log/fail2ban.log, the following output found:
  

  CONFIG_TEXT: fail2ban.filter        [XXXXX]: INFO    [ssh] Ignore 127.0.0.1 by ignoreself rule
  fail2ban.filter        [XXXXX]: INFO    [ssh] Ignore 127.0.0.1 by ignoreself rule

• In /var/log/secure the following output is found:
  

  CONFIG_TEXT: server sshd[XXXXX]: refused connect from 127.0.0.1 (127.0.0.1)
  server sshd[XXXXX]: refused connect from 127.0.0.1 (127.0.0.1)

• Fail2ban configuration has the following parameters set up:
  

  CONFIG_TEXT: # "ignorself" specifies whether the local resp. own IP addresses should be ignored
  # (default is true). Fail2ban will not ban a host which matches such addresses.
  ignorself = true
  
  # "ignoreip" can be a list of IP addresses, CIDR masks or DNS hosts. Fail2ban
  # will not ban a host which matches an address in this list. Several addresses
  # can be defined using space (and/or comma) separator.
  ignoreip = 127.0.0.1/8 ::1

Cause

Custom configurations causing refused connections from localhost (127.0.0.1)

Resolution

1. Login to the server via SSH
2. Open /etc/hosts.allow in any text editor and allow connections from localhost by adding:
   

   CONFIG_TEXT: sshd: 127.0.0.1 

3. Reload the sshd service:
   

   # systemctl reload sshd