LAN transmission methods refer to the way packets are sent on the network and are either unicast, multicast or broadcast.
CSMA/CD is a common LAN media access method.
Token ring is a LAN Topology.
LAN transmission protocols are the rules for communicating between computers on a LAN.
Common LAN transmission protocols are: polling and token-passing.
A LAN topology defines the manner in which the network devices are organized to facilitate communications.
Common LAN topologies are: bus, ring, star or meshed.
LAN transmission methods refer to the way packets are sent on the network and are either unicast, multicast or broadcast.
LAN media access methods control the use of a network (physical and data link layers).
They can be Ethernet, ARCnet, Token ring and FDDI.
Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the
Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 3:
Telecommunications and Network Security (page 103).
HERE IS A NICE OVERVIEW FROM CISCO:
LAN Transmission Methods
LAN data transmissions fall into three classifications: unicast, multicast, and broadcast.
In each type of transmission, a single packet is sent to one or more nodes.
In a unicast transmission, a single packet is sent from the source to a destination on a network. First, the source node addresses the packet by using the address of the destination node. The package is then sent onto the network, and finally, the network passes the packet to its destination.
A multicast transmission consists of a single data packet that is copied and sent to a specific subset of nodes on the network. First, the source node addresses the packet by using a multicast address. The packet is then sent into the network, which makes copies of the packet and sends a copy to each node that is part of the multicast address.
A broadcast transmission consists of a single data packet that is copied and sent to all nodes on the network. In these types of transmissions, the source node addresses the packet by using the broadcast address. The packet is then sent on to the network, which makes copies of the packet and sends a copy to every node on the network.
LAN Topologies
LAN topologies define the manner in which network devices are organized. Four common
LAN topologies exist: bus, ring, star, and tree. These topologies are logical architectures, but the actual devices need not be physically organized in these configurations. Logical bus and ring topologies, for example, are commonly organized physically as a star. A bus topology is a linear LAN architecture in which transmissions from network stations propagate the length of the medium and are received by all other stations. Of the three most widely used LAN implementations, Ethernet/IEEE 802.3 networks-including
100BaseT-implement a bus topology
Sources:
KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten
Domains of Computer Security, John Wiley & Sons, 2001, Chapter 3: Telecommunications and Network Security (page 104).
http://www.cisco.com/univercd/cc/td/doc/cisintwk/ito_doc/introlan.htm

AES is comprised of the three key sizes, 128, 192, and 256 bits with
a fixed block size of 128 bits. The Advanced Encryption Standard
(AES) was announced on November 26, 2001 , as Federal Information
Processing Standard Publication (FIPS PUB 197). FIPS PUB 197 states
that This standard may be used by Federal departments and agencies
when an agency determines that sensitive (unclassified) information
(as defined in P.L. 100-235) requires cryptographic protection.
Other FIPS-approved cryptographic algorithms may be used in addition
to, or in lieu of, this standard. Depending upon which of the
three keys is used, the standard may be referred to as AES-128,
AES-192 or AES-256.
The number of rounds used in the Rijndael cipher is a function of
the key size as follows:
256-bit key 14 rounds
192-bit key 12 rounds
128-bit key 10 rounds
Rijndael has a symmetric and parallel structure that provides for
flexibility of implementation and resistance to cryptanalytic attacks.
Attacks on Rijndael would involve the use of differential and linear
cryptanalysis.

A security policy is an important document to develop while designing an information system. The security policy begins with the organization's basic commitment to information security formulated as a general policy statement.
The policy is then applied to all aspects of the system design or security solution. The policy identifies security goals (e.g., confidentiality, integrity, availability, accountability, and assurance) the system should support, and these goals guide the procedures, standards and controls used in the IT security architecture design. The policy also should require definition of critical assets, the perceived threat, and security-related roles and responsibilities. Source: STONEBURNER, Gary & al, National Institute of Standards and Technology (NIST), NIST Special Publication 800-27, Engineering Principles for Information Technology Security (A Baseline for Achieving Security), June 2001 (page 6).

Media sanitization is the process of removing or destroying the data stored on a media device, such as a hard disk, a flash drive, or a CD-ROM, to prevent unauthorized access or disclosure. Media sanitization methods vary in their effectiveness and applicability, depending on the type and sensitivity of the data, the type and condition of the media, and the cost and feasibility of the method. For data with a high security categorization, which means that the data is classified or confidential and could cause severe damage or harm if compromised, the media sanitization methods that should be used are purge or destroy. Purge is a method that applies a strong magnetic field or a software algorithm to overwrite the data multiple times, making it unrecoverable by any means. Destroy is a method that physically damages or disintegrates the media device, making it unusable and unreadable. Clear or destroy is not a valid option, as clear is a method that applies a weak magnetic field or a software algorithm to overwrite the data once, making it unrecoverable by normal means, but not by advanced means. Clear or purge is also not a valid option, as clear is not sufficient for data with a high security categorization. Destroy or delete is also not a valid option, as delete is a method that removes the data from the file system, but not from the media device, making it recoverable by simple means. References: Official (ISC)2 Guide to the CISSP CBK, Fifth Edition, Chapter 7: Security Operations, page 346. CISSP All-in-One Exam Guide, Eighth Edition, Chapter 8: Business Continuity and Disaster Recovery Planning, page 483.