Into what two categories can you divide the OSI model?
Application (upper) and data transport (lower) layers.
What is the responsibility of the Data Transport layers of the OSI model?
Defining how data is sent accross the physical media, through Internetwork devices, to the destination computer and to application on the destination machine.
What is a physical topology?
It is a "map" or description of the layout of the network media that interconnects the devices on a network.
What is a logical topology?
It defines the way in which devices communicate and data is transmitted throughout the network.
What is the rule of thumb to distinguish physical from logical topologies?
If you can see it, it is physical; if you cannot see it or touch it, it is logical.
A topology affects the network's capabilities; what is the impact of choosing one topology over another?
Type of equipment the network needs; capabilities of the equipment; growth of the network; and way the network is managed?
What are the advantages of a bus topology?
Inexpensive to install; easy to add more workstations; requires less cable than other; works well for small networks (2-10 devices).
What are the disadvantages of a bus topology?
It's no longer a recommended option for new installations; if the backbone breaks, the network is down, only a limited number of devices can be included; it's difficult to isolate where a problem may be; and sharing the same cable means slower access time.
What are the advantages of a star topology?
It's easy to add more devices as your network expands; the failure of one cable or one cable break will not bring down the entire network; the hub provides centralized management; it's easy to find device and cable problems; a star network can be upgraded to faster network transmission speeds; and it's the most common topology, so many equipment options are available.
What are the disadvantages of a star topology?
A star network requires more media than a ring or bus network; the failure of the central hub can bring down the entire network; and the costs of installation and equipment are higher than for most bus networks.
What are the advantages of a ring topology?
Data packets can travel at greater speeds; there are no collisions; and it is easier to locate problems with devices and cable; and no terminators are needed.
What are the disadvantages of ring topology?
A ring network requires more cable than a bus network; a break int he cable will bring down many types of ring networks down when you add devices to the ring, all devices are suspended from using the network; and it's not as common as the bus topology; so there's not as much equipment available.
What are the two most common hybrid topologies?
Star-bus and star-ring topologies.
The easiest way to break down the many protocols of the TCP/IP suite is according to where they operate within the OSI model. Each protocol in this stack operates at what four layers?
The Data Link layer, the Network layer (also known as the Internet layer in the TCP/IP model), the Transport layer or the Application layer.
The protocols at the Data Link layer define the access method for the media, the architecture, and interface with the Physical layer of the network. What standards are these protocols based on?
The standards that have been adopted by the IEEE as the Project 802 standards.
What are the four most important TCP/IP protocols that function within the network layer?
Internet Protocol (IP), Address Resolution Protocol (ARP), Reverse Address Resolution Protocol (RARP) and Internet Control Message Protocol (ICMP).
What are the fields belonging to a TCP segment?
Source port, Destination port. Sequence number, Acknowledgment number (ACK), TCP header length, REservered, Flags, Sliding-window size (or window), Checksum, Urgent pointer, Options, Padding and Data.
What are some reasons for implementing DHCP?
To reduce time spent on IP address management, to reduce the potential for errors in assigning IP addresses and to make IP addressing transparent for mobile users.
What is a group of computers and devices that share a common communication line and resources in a small geographical area?
Local Area Network (LAN).
A local area network may serve how many users?
As few as two or three users or as many as thousands of users.
What type of network is also used as a means to interconnect several local area networks by bridging them with backbone lines?
A Metropolitan Area Network (MAN) or campus network.
What network provides a private tunnel through the Internet?
Virtual Private Network (VPN).
What type of computer port specifies a service that is a process or application that runs on a server and provides some benefit to a network user?
What is the port used when you do credit card transactions with e-commerce sites?
Port 443-SSL is the default port used when you do credit card transactions with an e-commerce site.
What are the two main parts of an IPv4 address?
Network and host number.
Who assigns network numbers?
IANA, ISP or OSP.
Convert 11000000 10101000 01111011 01100100 to dotted decimal notation.
What is the reserved IPv4 address for loop back?
What is the reservered IPv4 address for a limited broadcast?
What is a subnet mask?
It is a mechanism that allows a network device to divide an IP address into a network and host number.
What are the two methods of subnet masking?
Classful and classless.
What is the difference between the two methods of subnet masking?
Classful subnet masking is using the default mask to separate the network number, given by IANA, from the host number. Classless subnet masking borrows bits from the host field, extending beyond the default mask assigned by IANA and creating a subnet field.
What are some benefits to subnetting?
Ease of administration, improved network performance and security.
How long is an IPv6 address?
It is 128-bits or 16 octets long.
How is IPv6 address expressed?
16 byte fields, in colon hexadecimal format.
What are the two ways to shorten the expression of an IPv6 address?
Leading zero compression and zero compression.
What is a unicast address?
Address identity to a single interface.
What is a multicast address?
An address used to identify a group of interfaces belonging to different nodes starting with an address of FF00::/8.
What is an anycast address?
An address used to identify a set of interfacesl; but the packets are sent and accepted by the interface that is closest.
What are the three types of unicast address?
Link, site and global.
What is the IPv6 loop back address?
0:0:0:0:0:0:0:1: or ::1.
What are some tools available to transition from IPv4 to IPv6?
Dual IP layer/Dual Stack, Configured tunneling of IPv6 of IPv4, IPv4-compatible IPv6 addresses, and automatic tunneling of IPv6 over IPv4.