Chapter 5
What does Enhanced Interior Gateway Routing Protocol (EIGRP) means?
A dynamic link state protocol (developed by Cisco) Records transmission capacity, delay time, reliability and load for all paths Keeps the routing tables for its neighbors and uses this information in its routing decisions as well
Describe the anatomy of a router. How does a router differ from a computer?
A router consists of a CPU, memory, and ports or interfaces. A router differs from a computer because they are diskless and they don't come with a monitor, keyboard or mouse.
What is multicast messages.
A third type of message called a multicast message is used to send the same message to a group of computers.
What problems does dynamic addressing provide
Addresses can be leased for as long as the computer is connected to the network or for a specified time limit (e.g., two hours). When the lease expires, the client computer must contact the bootp or DHCP server to get a new address. Address leasing is commonly used by Internet service providers (ISPs) for dial-up users.
Explain how multicasting works
Any computer performing routing knows to route all multicast messages with this Class D IP address onto the subnet that contains the requesting computer. The routing computer sets the data link layer address on multicast messages to a matching multicast data link layer address.
What is the difference between decentralized routing and centralized routing?
Centralized routing is used typically only in host-based networks and in this case, routing decisions are rather simple. All computers are connected to the central computer by individual point-to-point circuits, so any message received is simply retransmitted on the point-to-point circuit connected to the destination. and Most decentralized routing protocols are self-adjusting, meaning that they can automatically adapt to changes in the network configuration (e.g., adding and deleting computers and circuits).
What are the 2 different address resolution?
Completely decentralized, Completely centralized.
Whats the differneces between UDP (user datagram Protacol) and TCP(Transmission Control Protocol)?
Connection-oriented routing has greater overhead than connectionless routing, because the sender must first "open" the circuit by sending a control packet that instructs all the intervening devices to establish the circuit routing. Likewise, when the transmission is complete, the sender must "close" the circuit. Connection-oriented protocols also tend to have more overhead bits in each packet.
How does DNS use UDP
Domain Name Server is primarily responsible for translating IP Addresses into valid Domain Names and translating valid Domain Names into IP addresses. UDP is a connection-less transport layer protocol. DNS would pass either a Domain Name or an IP address along with its packet(s) to the Transport layer for forwarding to the Network layer to be routed to the destination.
What does Border Gateway Protocol (BGP) means ?
Dynamic distance vector protocol used for exterior routing Far more complex than interior routing protocols Provide routing info only on selected routes (e.g., preferred or best route)
why do subnet networks need them?
Each of these LANs are called a TCP/IP subnet because they are logically grouped together by IP number. Knowing whether a computer is on your subnet or not it very important for message routing.
example of data link layer
Ethernet: 00-0C-00-F5-03-5A
What does Static means?
Fixed routing table, manually configured by network managers, local adjustments when computer added or removed.
What is de juro?
Formalized by an industry or government
How does HTTP use TCP
HTTP at the application layer would pass its message packet with overhead, including the Internet address of the destination, to the transport layer where TCP software would complete packetization at the Transport layer and hand it off to the Network layer.
What is data link layer address ?
If it is running Ethernet, then the network layer IP address would be translated into an Ethernet address
what are the formal routing protocol?
In MANs and WANs, the routing table for each computer is developed by its individual network manager
What is address resolution?
In order to send a message, the sender must be able to translate the application layer address (or server name) of the destination into a network layer address and in turn translate that into a data link layer address
What is broadcast.
In the situation of a broadcast message, the message is sent to all computers on a specific LAN or subnet.
What does IGMP stand for
Internet Group management protocol It is use in multicasting work.
the software that runs the mail server is referred to as the.
Mail transfer agent
What is a subnet mask comparison ?
On the other hand, if the subnet comparison shows that the message is not on that particular subnet, then the routing device will move the packets on in their journey.
How does TCP/IP perform address resolution for network layer addresses?
Server name resolution is the translation of application layer addresses into network layer addresses (e.g., translating an Internet address such as www.cba.uga.edu into an IP address such as 128.192.98.3). This is done using the Domain Name Service (DNS). Throughout the Internet there are a series of computers called name servers that provide DNS services.
What is de facto
Standard that emerge in the market place and are supported by several vernders but does not have an official standing.
What type of routing does a TCP/IP client use? What type of routing does a TCP/IP gateway use? Explain.
The TCP/IP client uses static routing because the client must always point to a single gateway router. The TCP/IP gateway router uses dynamic routing because typically it must process multiple requests for routing beyond the single segment that it physically supports
What is dynamic addressing provide?
The bootp or DHCP server can be configured to assign the same network layer address to the computer each time it requests an address (based on its data link layer address), or it can lease the address to the computer by picking the "next available" network layer address from a list of authorized addresses
What does the transport layer do?
The transport layer links application software in the application layer with the network and is responsible for the end-to-end delivery of the message. The transport layer sits between the application layer and the network layer. The transport layer accepts messages from the application layer and packetizes them
Which layer of the OSI model is responsible for ensuring flow control so that the destination station does not receive more packets that it can process at any given time.
Transport layer
How does TCP/Ip works with address resolution for the network layer addresses?
When TCP/IP needs to translate an application layer address into an IP address, it sends a special TCP-level packet to the nearest DNS server. This packet asks the DNS server to send the requesting computer the IP address that matches the Internet address provided. If the DNS server has a matching name in its database, it sends back a special TCP packet with the correct IP address. If that DNS server does not have that Internet address in its database, it will issue the same request to another DNS server elsewhere on the Internet.
Explain how the client computer in Figure 5.14 (128.192.98.xx) would obtain the data link layer address of its subnet gateway.
When a computer is installed on a TCP/IP network (or dials into a TCP/IP network), it knows the IP address of its subnet gateway. This information can be provided by a configuration file or via a bootp or DHCP server. However, the computer does not know the subnet gateway's Ethernet address (data link layer address). Therefore, TCP would broadcast an ARP request to all computers on its subnet, requesting that the computer whose IP address is 128.192.98.1 to respond with its Ethernet address. All computers on the subnet would process this request, but only the subnet gateway would respond with an ARP packet giving its Ethernet address. The network layer software on the client would then store this address in its data link layer address table.
What are the 3 functions of network layer.
addressing, routing, and breaking long messages into smaller packets for transmission by the data link layer
Which of the following statements is true about bandwidth?
bandwidth is constant across any wire, therefore distance is not relevant to its capacity
what does link state mean's?
based on the number of hops, circuit speed, and traffic congestion
What is a session?
can be thought of as a conversation between two computers. When the sender wants to send a message, it first establishes a session with the destination computer. The sender then sends the data packets in order until all data has been sent. Then the session is ended.
what does Completely decentralized mean?
each computer is responsible for knowing all address.
What benefits does dynamic addressing provide?
greatly simplifies network management in non-dial-up networks too. With dynamic addressing, address changes need to be done only to the bootp or DHCP server, not each individual computer. The next time each computer connects to the network or whenever the address lease expires, it automatically gets the new address
Example of network layer
internet prtocol: 129.79.127.4
What is routing?
is the process of determining the route or path through the network that a message will travel from the sending computer to the receiving computer. Every computer that performs routing has a routing table developed by the network manager that specifies how messages will travel through the network.
What are the parts of IP and what do they do
it performs packetizing: breaking the data into smaller packets, numbering them, ensuring each packet is reliably delivered, and putting them in the proper order at the destination. IP performs routing and addressing.
How does the subnet mask works with routing device?
number that each routing device on a network can use to compare the routing packet to in order to determine if the packet stays in that portion or the network, or should be routed on to the next portion of the network.
What is Quality of Service routing and why is it useful?
routing is a special type of connection-oriented dynamic routing in which different messages or packets are assigned different priorities
what is the definition of connection-less
routing means each packet is treated separately and makes its own way through the network. It is possible that different packets will take different routes through the network depending upon the type of routing used and the amount of traffic. Because packets following different routes may travel at different speeds, they may arrive out of sequence at their destination. The sender's network layer therefore puts a sequence number on each packet, in addition to information about the message stream to which the packet belongs. The network layer must reassemble them in the correct order before passing the message to the application layer.
What is the definition of Connection- oriented
routing sets up a virtual circuit between the sender and receiver. In this case, a temporary virtual circuit is defined between the sender and receiver. The network layer makes one routing decision when the connection is established, and all packets follow the same route. All packets in the same message arrive at the destination in the same order in which they were sent.
How does TCP establish a session ?
sets up a virtual circuit between the sender and the receiver. The transport layer software sends a special packet to the receiver requesting that a connection be established.
Which of the following is not a function of the data link layer?
specifying the type of connection, and the electrical signals, radio waves, or light pulses that pass through it.
what is the example of Quality of Service routing?
videoconferencing requires fast delivery of packet to ensure that the images and voices appear smooth and continuous; they are very time-dependent, because delays in routing will seriously affect the quality of the service provided.
example of a application layer ?
web browser: www.kelly.com