Question 81

Add a swap partition.
Adding an extra 500M swap partition to your system, this swap partition should mount automatically when the system starts up. Don't remove and modify the existing swap partitions on your system.

Question 82

Configure a task: plan to run echo "file" command at 14:23 every day.

Question 83

Add a new logical partition having size 100MB and create the data which will be the mount point for the new partition.

Question 84

Install the Kernel Upgrade.
Install suitable kernel update from:
http://server.domain11.example.com/pub/updates.
Following requirements must be met:
Updated kernel used as the default kernel of system start-up.
The original kernel is still valid and can be guided when system starts up.

Question 85

SIMULATION
Configure iptables, there are two domains in the network, the address of local domain is 172.24.0.0/16 other domain is 172.25.0.0/16, now refuse domain 172.25.0.0/16 to access the server.