##1. Problems connecting via ssh.##

If an attempt at ssh to a host has been denied, (although previously successful), 
you may get the following error:

`ssh_exchange_identification: read: Connection reset by peer`

This can be caused by an number of reasons. You can first try to delete the line containg the 
host from your ~/.ssh/known_host file. If this doesn't work then your ip address may be blocked 
and could be listed in the /etc/hosts.deny file.

To better diagnose the situation try connecting via ssh with the verbose option (-v or -vv) 
as this may provide some clues. A message that the connection has been reset by the peer could be 
further indication that the ip address is in the host.deny file.
Therefore check the file /etc/hosts.deny for the ip address. If the ip address is listed,
the following steps should then be followed:

	1. Stop the DenyHosts service:
	    
	    `$ systemctl stop denyhosts`
	    
	2. Remove the ip address from the following files:
	
	         1. `/etc/hosts.deny`
		 2. `/var/lib/denyhosts/hosts`
		 3. `/var/lib/denyhosts/hosts-restricted`
		 4. `/var/lib/denyhosts/hosts-root`
		 5. `/var/lib/denyhosts/hosts-valid`
		 6. `/var/lib/denyhosts/users-hosts`
	
	3. Start the DenyHosts service:
	    
	    `$ systemctl start denyhosts`
	    


###Refs:###

https://stackoverflow.com/questions/9225300/denyhosts-keeps-adding-back-my-ip