Chap2er 1-4 Flashcards
Sem 2 Chap 1-4
Switch recieves frame w unknown dest address. What happens?
Adds source MAC to table, forwards out of all ports except ingress
Switch component that reduces packet handling time
ASIC
Switching method that ensures frame is error-free
store-and-forward
Switching method without error checking
cut-through
What are frame forwarding decisions based on
MAC address and port mappings in CAM table
Difference between hub and switch
hub extends collision domain, switch divides collision domains
How many broadcast domains? (4 routers connected to hosts, each connected to a central router)
8
What impact does adding a switch have on a network
increases size of broadcast domain
How do switch buffers affect network performance
Store frames received, prevents premature frame discarding
Switch characteristic that keeps network local and alleviates network congestion
high port density
What happens when a device in a VLAN sends a broadcast frame
only devices in that VLAN see the frame
Characteristics of the native VLAN
traffic is untagged across the trunk, provides a common identifier to both ends of the trunk
VLAN designed to have <150ms delay
voice VLAN
VLAN used to separate networks into groups of users/devices
data VLAN
VLAN configured for SSH/Telnet/HTTPS/HTTP/SMTP
management VLAN
VLAN used to designate which traffic is untagged
native VLAN
VLAN type
a value for the tag protocol id value
VLAN ID
a VLAN number
VLAN User priority
a value that supports level or service implementation (QoS)
VLAN canonical format identifier
identifier that enables token ring frames to be carried across ethernet links
T/F: The command to assign a voice VLAN is switchport access vlan
FALSE
Four steps to configure voice VLAN
Add voice vlan, configure switch port in access mode, Assign voice vlan to source port, ensure voice traffic is trusted and tagged with CoS priority value
Output of show vlan brief
VLAN assignment and membership for all switch ports
Impact of no switchport access command
port is returned to vlan 1
What happens to switch ports after the VLAN to which they are assigned is deleted
ports stop communicating with the attached devices (the twilight zone)
Command to display encapsulation type, voice VLAN ID, and access mode VLAN for Fa0/1
show int Fa0/1 switchport
Why would interfaces be missing from show vlan brief
they’re configured as trunks
To be available, an interface must be
configured with an ip, manually activated
After which step of the switch bootup sequence is the boot loader executed
after POST execution
What does a switch use to locate and load the IOS image?
BOOT environment variable
Command used to set BOOT environment variable
boot system
Effect of “ip address” in interface config of switch
applies ipv4 address to virtual interface
If one end of ethernet is full-duplex and the other is half-duplex, where will collisions occur
at the half-duplex end
Command that displays info abt auto-mdix
show controllers
Runt frames are frames that are less than ___ bytes
64
T/F: The transport input all command will only allow ssh connections
FALSE
In order to be available, an interface must be
configured with at least one ip, activated with no shut
Characteristic of IPV4 loopback interface
logical interface internal to the router
DTP dynamic desirable
actively attempts to convert the link into a trunk
DTP dynamic auto
passively waits for neighbor to initiate trunking
DTP nonegociate
requires manual config of trunking/non-trunking
DTP trunk
permanent trunking mode
What mode should the router port be in if Cisco best practices are being used
trunk
Under what occasions should an admin disable DTP
when connecting cisco switch to non-cisco switch, on links that should not be trunking
Refer to the infographic where the workstations are on vlan 20. What is the problem
allow vlan 20 on the trunk link
Disadvantages of router-on-a-stick
dedicated router required, lower traffic flow speed
Correct statements regarding layer 3 switches (SVI inter-vlan)
switching packets is faster, no need for connection with router
What is required for communication between vlans (router-on-a-stick topology)
switch with router port configured as a trunk
What does in encapsulation dotiq mean
VLAN number
What command allows inter-vlan routing on a router
switchport mode trunk
What is the cause of the error “Configuring IP routing on a LAN… 802.1Q, or ISL VLAN”
missing encapsulation dot1q <>
What’s the problem in the exhibit with vlans 20,30, and 40 on RT1?
IP on sub-interfaces are incorrectly matched to VLANs
What kind of port is required for inter-vlan routing
trunk port
Characteristic of routed port on L3 switch
not assigned to a VLAN
What does in encapsulation dot1q mean
VLAN number
Problems in Gi1/1 exhibit
Gi1/1 is the default VLAN, Gi1/1 is configured as a turnk
How to do packet tracer
fix router-on-a-stick
