1. MTA Network Fundamental Cram Sesion
Mark Rawlings

2. Network Topology
A network topology defines the physical connections of hosts in a computer network.
There are several types of physical topologies including:
Bus
Ring
Star
Mesh
Tree

3. Star Topology Most Common topology
Each computer is individually wired to a central connecting device (hub, switch or SOHO router) with twisted-pair cabling.

4. Mesh Topology
Every computer connects to every other computer; no central connecting device is needed.

5. Ring Topology
In a LAN environment, each computer is connected to the network using a closed loop.
Used by Token Ring and FDDI.

6. Token Ring
A Token Ring network sends data logically in a ring fashion, meaning that a token goes to each computer, one at a time, and continues on in cycles.
However, Token Ring computers are physically connected in a star fashion.
Namely, all computers in a Token Ring network are connected to a central connecting device known as a Multistation Access Unit (MAU or MSAU).

7. Ethernet
Ethernet is a group of networking technologies that define how information is sent and received between network adapters, hubs, switches, and other devices.
Ethernet is the de facto standard and has the largest share of networks in place today.
Ethernet is standardized by the Institute of Electrical and Electronics Engineers (IEEE) as

8. Ports

9. Ports
It is important to understand the difference between inbound and outbound ports:
Inbound ports
Outbound ports

10. Ports

11. NetStat Command
This will display a list of all the connections to and from your computer in numeric format

12. OSI Model Revisited

13. WLAN Standards

14. Wireless Encryption Options

15. Classful Network Architecture

16. Loopback Testing The range for Class A is 0–127.
The 127 network number isn’t used by hosts as a logical IP address. Instead, this network is used for loopback IP addresses, which allow for testing.

17. Private Addresses

18. APIPA APIPA is an acronym for Automatic Private IP Addressing.
It uses a single Class B network number:
If a Windows client cannot get an IP address from a DHCP server and has not been configured statically, it will auto-assign a number on this network.

19. IPConfig Command
Displays IP Configuration

20. IPConfig /All Command

21. IPConfig /Release

22. Ping Command
Used to test network connectivity
Users ICMP

23. Tracert Command W

24. PathPing Command

25. NetStat Command

26. NSLookup
Nslookup displays information about DNS names and their corresponding IP addresses, and it can be used to diagnose DNS servers.

27. IPSec
Internet Protocol Security (IPSec) is a protocol within the TCP/IP suite that encrypts and authenticates IP packets.
It is designed to secure any application traffic because it resides on the network layer (or Internet layer, as TCP/IP programmers refer to it).
This protocol is used in conjunction with virtual private networks and is an integral part of IPv6.

28. WINS
Windows Internet Name Service (WINS) is a service that resolves NetBIOS names to IP addresses.
It is Microsoft’s version of the NetBIOS Name Service (NBNS) combined with a name server.

29. T-Carriers The two most common T-carrier systems are as follows:
T1: It is considered Mbps, but only Mbps of that is for data.
The Mbps is broken into 24 equal 64 Kbps channels and can be used with a multiplexor.
T3: Stands for trunk Carrier 3.
Equivalent of 28 T1s. It is considered Mbps, using Kbps B channels.

30. DSL
Digital subscriber line (DSL) is a family of technologies that provides data transmissions over local telephone networks.
xDSL is the standard for the various digital subscriber lines.
ADSL (asymmetrical digital subscriber lines) can run on your home telephone line so that you can talk on the phone and access the Internet at the same time.
SDSL (symmetrical digital subscriber line) is installed (usually to companies) as a separate line and is more expensive. The upload and download speed are the same or symmetrical.

31. VPN Popular VPN Protocols are:
PPTP: generally includes security mechanisms, and no additional software or protocols need to be loaded.
L2TP with IPSec: L2TP not normally encrypted – IP Sec added for encryption
Site to Site VPN: Establishes a secure connection over public web
SSL VPN: Used with standard web browser – no install needed

32. Point-to-Point Tunneling Protocol
Point-to-Point Tunneling Protocol (PPTP) is the more commonly used protocol, but it is also the less secure option.
PPTP generally includes security mechanisms, and no additional software or protocols need to be loaded.
A VPN device or server that allows incoming PPTP connections must have inbound port 1723 open.
PPTP works within the point-to-point protocol (PPP), which is also used for dial-up connections.

33. L2TP with IPSec
Layer 2 Tunneling Protocol (L2TP) is quickly gaining popularity due to the inclusion of IPsec as its security protocol.
Although this is a separate protocol and L2TP doesn’t have any inherent security,
L2TP is considered the more secure solution because IPsec is required in most L2TP implementations.
A VPN device or server that allows incoming L2TP connections must have inbound port 1701 open.

34. DMZ