The IT Stuff

Denial-of-Service Attack:
In DOS Attack after gaining access to your network, the attacker can do any of the following:

Randomize the attention of your internal Information Systems staff so that they do not see the intrusion immediately, which allows the attacker to make more attacks during the diversion.
Send invalid data to applications or network services, which causes [...]

Internetworking involves connecting two or more computer networks via gateways(router etc) using a common routing technology. The result is called an internetwork (often shortened to internet).Or  is a collection of individual networks, connected by intermediate networking devices(router,ATM Switch etc) , that functions as a single large network.

Sservices as a comprehensive term for all the concepts, [...]

IPv4 (Internet Protocol version 4)
The current generation of IP, in which an IP address has two parts: The first is the network ID and the second is the host ID. Under IPv4, there are five classes (Class A through Class E), which differ in how many networks and hosts are supported.
IPv6 (Internet Protocol version 6)
An [...]

The next generation of internet expanded address format will use IP version six (Ipv6) which is currently being used in some test and early adopter networks.
An IP addressing scheme that uses a 128-bit address, which allows a total of 340 billion billion billion billion unique addresses. IPv6 offers many benefits, but it requires a major [...]

The Cisco access control list (ACL) is  used not only used for packet filtering (a type of firewall) but also for selecting types of traffic to be analyzed, forwarded, or influenced in some way.
Cisco ACLs are divided into types.

Standard IP ACL,
Extended IP ACL.

Standard IP Access Lists:
A Standard Access List only allows you to permit or [...]