Ch. 4 Fundamentals Of IPv4 Addressing And Routing Flashcards
Addresses used to identify a packets source and destination host computer, addressing rules also organize addresses into groups which greatly assist the writing process
IP addressing
The process of hosts and routers forwarding IP packets (layer 3 PDUs) while relying on the underlying LANs and WANs to forward the bits
IP routing
Protocol that aids routers by dynamically learning about IP address groups so that the router knows where to route IP packets so that they go to the right destination host
IP routing protocol
The network layer also relies on other utilities for TCP/IP the utility’s include domain name system (DNS) address resolution protocol (ARP) and ping
Other utilities
DNS
Domain name system
ARP
Address resolution protocol
IP focuses on the job of
Routing data
IP does not concern itself with
The physical transmission of data
IP relies on ______ ______ ______to do the physical transmission of the data
Lower TCP/IP layers
IP concerns itself with _____ _____ instead of physical details of delivering data
Logical details
Routers and end user computers called _____ in a TCP/IP network work together to perform IP routing
Hosts
The term _____ ______ is sometimes used to refer the routing process, at other times it refers to the routing protocols specifically how routing protocols select the best route among the competing routes to the same destination
Path selection
The default router is also referred to as
The default gateway
The table that lists IP address groupings is called
IP routing table
IP address groupings are made up of____ and _____
IP networks and IP subnets
The _____ ______ layer adds the appropriate header and trailer to the packet creating a frame before sending the frames over each physical network
Data link
______ dynamically learns the data link address of an IP’s host connected to a LAN
ARP (address resolution protocol)
How does a router determine which data at link address to use
Via ARP
What are the two main topics routing has covered so far
Forwarding Layer 3 packets also known as PDU
Encapsulating layer 3 packets in the later 2 frames for Transmission
____ defines network layer addresses that identify any host or router interface That connect to a TCP/IP network
IP
TCP/IP groups IP addresses together so that IP addresses used on the same physical network are part of the same group, these groups are known as _____ or ______
IP network or an IP subnet
Network layer protocols group addresses both by their _____ and by the actual_____ ______
Location
Address values
Hosts need to know the IP address of their ______ ______ so that hosts can send packets to promote destiny
Default router
Routers need to know ______ so that routers know how to forward packets to each and every IP networking IP subnet
Routes
Most network engineers enable a _______ _______ on all their routers. When enabled within a TCP/IP network with the correct settings routers send messages to each other and learn all the IP networks and subnets for the TCP/IP internetwork
Routing protocol
What is the most important topic for the CCENT and CCNA exams
IPv4
If the device want to communicate using TCP/IP it needs an _____ _____
IP address
When a device has an IP address and appropriate software and hardware it can send and receive _____ _____
IP packets
Any device that has at least one interface with an IP address can send and receive IP packets and it’s called an ____ ____
IP host
IP addresses consist of a ____ _____ number usually written and dotted decimal notation DDN
32-bit
How many bits are in a byte
8
Each DDN has four decimal ____ separated by periods
Octets
The term octet is just a vendor neutral term for
A byte
The range of decimal numbers and each octet is between ___ and ___
0 and 255
Each network interface uses a unique
IP address
If a laptop has both an ethernet network interface card NIC and a wireless NIC with both working at the same time at the same time both will have an_____ _____
IP address
The original specifications for TCP/IP group IP addresses into sets of consecutive addresses called. _____ ____
IP networks
The addresses in a single IP network have the same ______ ______ in the first part of all addresses in the network
Numeric value
All IP addresses in the same group must not be separate from each other by a
Router
IP addresses separated from each other by a ______ must be in different groups
Router
IP routing relies on all addresses and one IP network or IP subnet to be in the same ______
Location
Class A IP networks Receive DDN numbers that begin with ____ to ____
1 through 126
Class B IP networks received DDN numbers that be begin with _____ to _____
128 through 191
Class C IP networks receive DDN numbers that begin with _____ to ____
192 through 223
Class a B and C addresses are all_____
Unicast
Class D IP networks receive numbers that begin with ____ to _____
224 through 239
Class D networks are ______
Multicast
Class E IP networks receive numbers that begin with ____ to ____
240 through 255
Class E networks are considered
Experimental
Class A networks each support very large number of IP addresses (over 16 million hosts) however because each class A network is so large class A only holds _____class A networks
126
Class B defines IP networks that have _____ addresses per network but with space for over _____ such networks
65,534
16,000
Class C defines much smaller IP networks with _____ addresses each
254
Network ID
Network identifier
The ______ ______ is just one reserved DDN value per network that identifies the IP network
Network ID
The _____ _____ cannot be used by host as an IP address
Network ID
Network number and network address are common terms also used to describe the _____ _____
Network ID
The term _____ ______ _____the first to any class A B or C network because it is defined by class a B and C rules
Classful IP network
Class A octet range is _____ to _____
1 to 126
Class A valid network numbers are _____ to _____
1.0.0.0 to 126.0.0.0
Class B octet range is ____ to ____
128 to 191
Class B valid network numbers are ____ to ____
128.0.0.0 to 191.255.0.0
Class C octet range is ____ to _____
192 to 223
Class C valid network numbers are ____ to _____
192.0.0.0 to 223.255.255.0
______ defines methods of further subdividing IPv4 address space into groups that are smaller than a single IP network
Subnetting
_____ is shorthand for subdivided network
Subnet
A network made up of routers switches cables and other equipment is called a_____
Internetwork
150.9.1.0 - 150.9.4.0 - 150.9.5.0 - 150.9.2.0 - 150.9.3.0 are all ______ of class B network 150.9.0.0
Subnets
Host use simple routing logic when choosing where to send the packet if you assume that the design uses subsets this two-step logic is:
If the destination IP addresses in the same IP subnet as I am send the packets directly to that destination host
Otherwise send the packet to my default gateway also known as a default router
The destination IP address is in the same subnet send that package directly to the destination host otherwise:
Send it to my default gateway
What are the first two steps a router does when a frame arrives
Uses Frame check sequence (FCS) to ensure that the frame had no errors, if errors occurred discard the frame
Assuming the frame is not discarded at step one, discard the old data link header and trailer leaving IP packet
What are the third and fourth steps a router does arrives
Compare IP packets destination IP address to the routing table and find the route the best matches the destination address
Encapsulate the packet inside a new datalink header and trailer appropriate for the outgoing interface and forward the frame
What step in router forwarding logic is the main step
Step 3. Compare the IP packets destination IP address to the routing table and find the route the best matches the destination address
OSPF
Open shortest Path first
These are all:
Dynamically learning and filling the routing table with the route to each subnet in the internetwork
if more than one route to a subnet is available to place the best route in the routing table
To notice when routes in the table are no longer valid it’s remove them from the routing table
If a route is removed from the routing table and another route through another neighboring router is available to add the route to the routing table
To work quickly when adding new routes or replacing lost routes
To prevent routing loops
The goals of a routing protocol
The time between losing a route and finding a working replacement route is called ______ _____
Convergence time
When a new router sends a protocol message informing them subnet of a new route it is called
Routing update
TCP/IP defined a way to use ______ _____ to identify other computers
Host names
TCP/IP uses _____ _____ _____ to find an IP address used by the listed host name
Domain name system (DNS)
In order to determine a IP address with a host name a ____ ____ is sent to a DNS server. the DNS server sends back a DNS reply that list the IP address for the given host name
DNS query
The method by which any host or motor on the LAN can dynamically learn the Mac address of another IP host or router on the same LAN is called
Address resolution protocol (ARP)
If A message ask the simple request “is this your IP address please reply with your MAC address” it is known as an
ARP request
A response for a MAC address is called a
ARP reply
A host will check a ____ _____ to see if it has a MAC address before sending out an ARP request
ARP cache
A ____ ____ is generated as a host learns MAC addresses for other hosts
ARP cache
What is the command to see the contents of the ARP cache on most PC operating system
arp -a
How do you test basic IP connectivity without relying on any applications to be working
Use the Ping command
Ping
Packet Internet groper
ICMP
Internet control message protocol
A ping will send a ____ ____ and receive a ____ _____
Echo request
Echo reply
What are the functions of OSI layer 3 (network layer) protocols
Logical addressing and path selection
PC 1 needs to send some data to PC 2. PC 1 and PC 2 are separated by several routers and sit on different ethernet LANs. What are the largest entities (in size) that make it from PC 1 to PC 2
Packet and L3 PDU
Which of the following is a valid class C IP address that can be assigned to host:
- 1.1.1
- 1.1.1
- 128.128.128
- 1.1.1
- 223.223.255
200.1.1.1
What is the assignable range of values for the first octet for class A IP networks
1 to 126
PC1 and PC2 are on two different ethernet LANs that are separated by an IP router PC1’s IP address is 10.1.1.1, and no subnetting is used. Which of the following addresses could be used for PC2 (choose two)
- 1.1.2
- 2.2.2
- 200.200.1
- 1.1.1
- 1.1.1
- 1.1,1
- 1.1.1
1. 1.1.1
What does a router normally use when making decisions about writing TCP/IP packets
Destination IP address
Which of the following are true about a LAN connected TCP/IP host and it’s IP routing choices (choose two)
The host always sends packets to it’s default gateway
The host sends packets to it’s default gateway if the destination IP address is in a different class of IP network than the host
The host sends packets to it’s default gateway if the destination IP address is in a different subnet than the host
The host sends packets to it’s default gateway if the destination IP addresses in the same subnet as the host
The host sends packets to it’s default gateway if the destination IP address is in a different class of IP network then the host
The host sends packets to it’s default gateway if the destination IP address is in a different subnet them the host
Which of the following are functions of a routing protocol (choose 2)
Advertising known routes to neighboring routes
Learning routes for subnets directly connected to the router
Learning routes and putting those routes into the routing table for routes advertised to the router by its neighboring routers
Forwarding IP packets based on a packets destination IP address
Advertising known routes to neighboring routes
Learning routes and putting those routes into the routing table for routes advertised to the router by its neighboring routers
A company implements a TCP/IP network. With PC1 sitting on an ethernet LAN. which of the following protocols and features requires PC1 to learn information from some other device
DNS
