CISCO CH 05
What is the Layer 2 multicast MAC address that corresponds to the Layer 3 IPv4 multicast address 224.139.34.56?
01-00-5E-0B-22-38
Fill in the blank. The binary number 0000 1010 can be expressed as ______ in hexadecimal.
0A
Which two statements describe features or functions of the logical link control sublayer in Ethernet standards? (Choose two.)
1. Logical link control is implemented in software. 2. The data link layer uses LLC to communicate with the upper layers of the protocol suite.
this type of memory buffering is used in asymmetric switching
SHARED MEMORY BUFFERING
THIS FIELD IS READ BY A SWITCH TO POPULATE ITS MAC ADDRESS TABLE
SOURCE MAC ADDRESS FIELD
When a device receives an ARP request for a device with a different IP address, it will use the _______ information to update its ARP table and then it will _______ the packet.
SOURCE. DROP.
What type of switching is used on current L2 switches to allow QoS?
STORE-AND-FORWARD
this frame forwarding method reads the entire frame including the FCS field
STORE-AND-FORWARD
what are the primary functions associated with data encapsulation at the ethernet MAC sublayer?
frame delimiting, addressing, error detection
Which address is a multicast MAC address?
01-00-5E
type of frame ARP uses
BROADCAST
these 2 situations are when a switch will flood a frame to all ports except the one it came in on.
BROADCAST FRAME. DESTINATION NOT IN THE MAC ADDRESS TABLE.
Which statement is true about MAC addresses?
The first 3 bytes are used by the vendor assigned OUI.
which layers of the OSI model does ethernet function?
data link & physical
Which two statements are correct about MAC and IP addresses during data transmission if NAT is not involved? (Choose two.)
1. Destination & source MAC addresses have local significance and change every time a frame goes from one LAN to another. 2. Destination IP address in a packet header remains constant along the entire path to a target host.
Which two statements describe a fixed configuration Ethernet switch? (Choose two.)
1. Fixed configuration switch may be stackable. 2. The number of ports on the switch cannot be increased.
What are two features of ARP? (Choose two.)
1. If a host is ready to send a packet to a local destination device and it has the IP address but not the MAC address of the destination, it generates an ARP broadcast. 2. If a device receiving an ARP request has the destination IPv4 address, it responds with an ARP reply.
What are two potential network problems that can result from ARP operation? (Choose two.)
1. On large networks with low bandwidth, multiple ARP broadcasts could cause data communication delays. 2. Network attackers could manipulate MAC address and IP address mappings in ARP messages with the intent of intercepting network traffic.
A network administrator is connecting two modern switches using a straight-through cable. The switches are new and have never been configured. Which three statements are correct about the final result of the connection? (Choose three.)
1. The link between the switches will work at the fastest speed that is supported by both switches. 2. The link between switches will work as full-duplex. 3. The auto-MDIX feature will configure the interfaces eliminating the need for a crossover cable.
What is the minimum & maximum Ethernet frame size as defined by IEEE 802.3 ?
64 BYTES - 1518 BYTES
used by hackers to direct traffic to incorrect hosts
ARP SPOOFING
When ARP receives a request to map an IPV4 address to a MAC address, i t first looks in its ________ . If no entry is found, ARP will send out an ARP _______.
ARP TABLE / ARP CACHE. REQUEST.
Match the characteristic to forwarding method:
A store-and-forward switch always stores the entire frame before forwarding, and checks its CRC and frame length. A cut-through switch can forward frames before receiving the destination address field, thus presenting less latency than a store-and-forward switch. Because the frame can begin to be forwarded before it is completely received, the switch may transmit a corrupt or runt frame. All forwarding methods require a Layer 2 switch to forward broadcast frames.
Which devices on a network will hear an ARP request?
ALL DEVICES IN THE L2 BROADCAST DOMAIN
What happens when data collision occurs on an Ethernet bus?
ALL DEVICES STOP TRANSMITTING & TRY AGAIN LATER
this feature will correct incorrect use of cables on newer switches
AUTO MDIX
How does adding an Ethernet line card affect the form factor of a switch?
By expanding the port density
The MAC address table is sometimes referred to as a _____ table because it is stored in _______ memory.
CAM. CONTENT ADDRESSABLE.
carrier sense used for wireless
CSMA/CA
resolves contention based issues on a shared ethernet medium
CSMA/CD
What statement illustrates a drawback of the CSMA/CD access method?
Collisions can decrease network performance.
this switch cut-through forwarding method could forward bad or runt frames
FAST-FORWARD
Which address is used as a destination address on a broadcast Ethernet frame?
FF-FF-FF-FF-FF-FF
what is the name given to the Ethernet MAC sublayer PDU ?
FRAME
Which field in an Ethernet frame is used for error detection?
FRAME CHECK SEQUENCE
which standard specifies the ethernet MAC sublayer functionality in a computer NIC?
IEEE 802.3
What is a characteristic of a contention-based access method?
It is a nondeterministic method.
A host is trying to send a packet to a device on a remote LAN segment, but there are currently no mappings in its ARP cache. How will the device obtain a destination MAC address?
It will send an ARP request for the MAC address of the default gateway.
this type of switch can perform switching based on IP addresses
LAYER 3 SWITCH
this sublayer of the datalink layer is software based and connects to the upper layers
LLC
THESE FIELDS ARE 6 BYTES EACH
MAC ADDRESS FIELDS
this is result of an ARP request when PC-A is looking for a host address on the local LAN of PC-B
MAC ADDRESS OF PC-B
this is where switches save port to MAC address mappings
MAC ADDRESS TABLE
When a switch receives a broadcast frame, it enters the source information in its ________ and then it _______ the frame to all ports except the one port the frame was _______ on.
MAC ADDRESS TABLE. FLOODS. RECEIVED.
this sublayer of datalink is hardware based, interacts w drivers and puts frames on links
MAC LAYER
what a host needs when it creates an ARP request
MAC address of a known IP address
Which address or combination of addresses does a Layer 3 switch use to make forwarding decisions?
MAC and IP addresses
To configure a routed port, the interface must be put into Layer 3 mode by using the _______ interface configuration command. After this, the interface must be assigned an _____ address.
NO SWITCHPORT. IP.
Refer to the exhibit. PC1 issues an ARP request because it needs to send a packet to PC2. In this scenario, what will happen next?
PC2 will send an ARP reply with its MAC address.
this frame field is found at beginning of ethernet frame and is used for synch between sending and rec'ing devices
PREAMBLE
What functions are provided by the ARP process?
RESOLVING IPV4 ADDRESSES TO MAC ADDRESSES. MAINTAINING A TABLE OF MAPPINGS
What name is given to a physical port on a Layer 3 switch configured to act as a router port?
ROUTED PORT.
What is true about the Ethernet MAC address?
THE FIRST 6 HEXADECIMAL DIGITS OF A MAC ADDRESS REPRESENT THE OUI. THE VENDOR IS RESPONSIBLE FOR ASSIGNING THE LAST 24 BITS OF THE MAC ADDRESS. THE MAC ADDRESS IS ALSO KNOWN AS A "BURNED-IN-ADDRESS"
Refer to the exhibit. The exhibit shows a small switched network and the contents of the MAC address table of the switch. PC1 has sent a frame addressed to PC3. What will the switch do with the frame?
The switch will forward the frame to all ports except port 4.
ARP REQUESTS are sent to a broadcast MAC address, and ARP replies are sent to a ________ MAC address.
UNICAST.
A network administrator issues the following commands on a Layer 3 switch: DLS1(config)# interface f0/3 DLS1(config-if)# no switchport DLS1(config-if)# ip address 172.16.0.1 255.255.255.0 DLS1(config-if)# no shutdown DLS1(config-if)# end What is the administrator configuring?
configuring a routed port
What is the purpose of the preamble in an Ethernet frame?
is used for timing synchronization
A Layer 2 switch is used to switch incoming frames from a 1000BASE-T port to a port connected to a 100Base-T network. Which method of memory buffering would work best for this task?
shared memory buffering
When would a switch record multiple entries for a single switch port in its MAC address table?
when another switch is connected to the switch port