The collection of all the protocols and processes
Bus Topology
·
A network layout in
which there is one main trunk, or backbone, that all the various computers and
network devices are connected to.
Ring Topology
·
A LAN configuration in
which all nodes are connected in a closed loop
Star Topology
·
A topology with one
central node that has each computer or network device attached to the central
node. All data first goes into the central node and then is sent out to its
destination. (Think of it like a bicycle wheel with spokes.)
Mesh Topology
·
Every node is
connected to every other node.
OSI Layer 1 - Physical
Layer
·
Covers cabling and
other connection mediums. Defines relationship between device and physical
means of sending data over network. Defines optical, electrical, and mechanical
characteristics.
OSI Layer 2 - Data
Link Layer
·
Includes Ethernet
standard and unique hardware addresses. Defines procedures for operating the
comm links, encapsulates data, and detects and corrects packet-transmission
errors.
OSI Layer 3 (Network
Layer)
·
IP comes into play.
Determines how data is transferred, routes packets according to network device
addresses, and provides flow and congestion control to prevent network resource
depletion.
OSI Layer 4 -
Transport Layer
·
Governs the transfer
of data. Provides packet delivery, connection-oriented or connection-less
packet delivery, and provides flow and congestion control to prevent network
resource depletion.
OSI Layer 5 - Session
Layer
·
1st Upper layer and
concerns the data itself, ensuring data passes properly through the network.
Manages user sessions and dialogues, controls the establishment and termination
of connections, and reports upper-layer problems.
OSI Layer 6 -
Presentation Layer
·
Unpackages data for
use by application layer, makes data format differences between dissimilar
systems so they can communicate, specifies an architechture-independent
data-transfer format, and encodes/decodes data, encrypts/decrypts data, and
compresses/decompresses data.
OSI Layer 7 -
Application Layer
·
presents data to the
application software for use, defines an interface to user processes for
communication and data transfer, and provides standardized services.
Protocol (network)
·
The ruleset that
defines how information is transferred.
TCP/IP Suite
·
The collection of all
the protocols and processes that make TCP over IP communication over a network
possible.
SSH 22
·
SSH is the primary
method used to manage network devices securely at the command level. It is
typically used as a secure alternative to Telnet which does not support secure
connections.
DNS 53
·
The DNS is used widely
on the public internet and on private networks to translate domain names into
IP addresses, typically for network routing. DNS is hieratical with main root
servers that contain databases that list the managers of high level Top Level
Domains (TLD) (such as .com). These different TLD managers then contain
information for the second level domains that are typically used by individual
users (for example, cisco.com). A DNS server can also be set up within a
private network to private naming services between the hosts of the internal
network without being part of the global system.
SMTP 25
·
SMTP is used for two
primary functions, it is used to transfer mail (email) from source to
destination between mail servers and it is used by end users to send email to a
mail system.
SFTP 22
·
A secure version of
FTP.
FTP 20, 21
·
A file transfer
protocol, used for unsecured file transfers.
TFTP 69
·
Trivial File Transfer
Protcol, used for primarily node booting.
TELNET 23
·
Insecure console
access, replaced quickly by SSH.
DHCP
·
67, 68 Dynamic Host
Config Protocol, used to automatically configure IP addresses, default
gateways, etc.
HTTP
·
80, HyperText Transfer
Protocol, Used to transfer text and simple scripts to a web browser.
HTTPS
·
443, secure version of
HTTP.
SNMP
- UDP 161, 162
- Part of the TCP/IP suite, this protocol shares information devices on a
network for management purposes.
RDP
·
3389, allows for
remote desktop access.
NTP
·
123, Network Time
Protocol, used for networks that require specific timings.
SIP
·
5060/5061 Session
Initiation Protocol, used for maintaining sessions including VoIP, Video, or
messaging.
SMB
·
445, Server Message
Block, Provided shared access to files, printers, and ports.
>>>>>>BLOCK THIS PORT<<<<<
POP
·
110, retrieves mail
from a remote server.
IMAP
·
143, Internet Message
Access Protocol, Stores mail on remote server, but allows clients to access it.
LDAP
·
389, Lightweight
Directory Access Protocol, allows for windows directory accessing.
LDAPS
·
636, Secure LDAP
H.232
·
1720, Provides basic
services to videophones/telephones such as hold, pickups, and other services.
client/server network
·
A network that uses
centrally administered computers, known as servers, to enable resource sharing
for and to facilitate communication between the other computers on the network.
Personal Area Network
(PAN)
·
provides communication
for devices owned by a single user that work over a short distance
Local Area Network
(LAN)
·
Connects a group of
computers in close proximity, such as in an office building, school, or home
Wireless Local Area
Network (WLAN)
·
A wireless network
designed to replace or supplement a wired local area network (LAN).
Metropolitan Area
Network (MAN)
·
network that spans a
metropolitan area, usually a city and its major suburbs. Its geographic scope
falls between a WAN and a LAN
Wide Area Network
(WAN)
·
Spans a large
geographic area such as a state, province, or country
Network
·
a group of two or more
computer systems linked together
Subnet
·
A logical subset of a
larger network, created by an administrator to improve network performance or
to provide security.
Internetwork
·
Network of networks
which consists of two or more physical networks.
Internet
·
A global network
connecting millions of computers, making it possible to exchange information.
Intranet
·
a network designed for
the exclusive use of computer users within an organization that cannot be
accessed by users outside the organization
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