To alleviate security concerns, you may want to restrict administrative access to your control panel by IP address.
How to allow administrative access to Plesk Control interface only from specific IP addresses or networks
1 Go to the Server page and click the "Server button" in the "System menu".
2 Click Add New Network and specify the required IP addresses. Click OK. To specify subnets, you can use wildcard symbols (*) and subnet masks.
3 Select the Denied from the networks that are not listed option, and click Set. When prompted to confirm the operation, click OK.
How to prohibit administrative access from specific IP addresses or networks
1 Go to Server > Access.
2 Click Add New Network and specify an IP address. Click OK. To specify subnets, you can use wildcard symbols (*) and subnet masks.
3 Select the Allowed, excluding the networks in the list option, and click Set. When prompted to confirm the operation, click OK.
Tip :By default Plesk allows multiple simultaneous
sessions for several users logged into the control panel using the same
login and password combination. This can be useful when delegating
management functions to other users or in case if you accidentally
close your browser without logging out, thus becoming unable to log in
again until your session expires. You may want to switch off this
capability if you do not need it.