Nov 11 Test Flashcards
(9 cards)
What are the two parts of an IP address?
Host ID and Network ID
What is used to define the host and network portion of an IP address?
The subnet mask is used to define which parts of the IP address are network ID and host ID. To do this you must perform a logical AND to compare the subnet mask with the ip address.
Describe csma/cd
csma stands for carrier sense multiple access, the ‘cd’ means collision detection. This means that if two devices transmit at the same time, they will both detect the imminent collision, and both wait a short/random amount of time before attempting to re transmit.
describe csma/ca
the csma stands for carrier sense multiple access. the ‘ca’ stands for collision avoidance. This means that instead of detecting a collision, they try to avoid them entirely by waiting to transmit their data. A device will begin by transmitting the amount of time that they need to send their data, and the other devices on the network wil know that the network is unavailable and wait their turn basically. this does not work well under heavy use/large networks.
What are two ways to express netmasks?
Cidr, and dotted decimal. Cidr is basically putting a “/” after the IP address with the number of bits. whereas dotted decimal looks a lot more traditional, and is the same type of notation used in the ip address.
Frame sizes…and GO
Frames are between 46 and 1500 bits. a fram smaller than 46 is called a runt frame. anything bigger than 1500 is considered a JUMBO frame. (not mondo)
describe a private ip address and how it is different from a regular one.
it is a non-unique ip address that some companies use on their internal network. it is not routable on the outside network. however, by using Nat, it is possible to connect to the outside world.
what is an octet?
it is a piece of the ip address separated from the others by a decimal. there are 4 octets in an ip address.
describe arp.
arp(address resolution protocol) is used when a computer on a network does not know the mac address of the computer it wishes to connect with. it will send a broadcast packet to the switch. the switch will look for the destination of the packet, and instead of finding a mac it will find a bunch of fs. It will realize that the sender does not know the mac of the receiver, and to broadcast the packet. it will flood the frame. (send the packet to every port on the switch) The computer which has the matching ip address will see the broadcast and say, hey! thats me! it will send and arp reply back to the switch. and the switch can send it directly to the first computer.
Computer A now knows the mac address of the other computer.
