Layer 2 Switching Flashcards
When you use a set of bridges and routers to segment your LAN into smaller networks, what results will you get?
(1) Decreased congestion on each segment, and (2) increased number of collision domains.
When you segment a network with a router, what results will you get?
(1) Fewer devices per broadcast domain and (2) increased number of collision domains.
Will connection hosts and servers to their own dedicated port on a switch reduce the broadcast domains?
No, broadcast packets will be sent to all ports.
Describe cut-through switching
The switch copies only the destination address of the frame into its buffer and the switch reduces latency by forwarding the frame almost immediately.
Describe fragment-free switching.
The switch reads the first 64 bytes of the frame, verifies that a collision has not occurred, and switches the frame to the correct port.
What is a collision domain?
Networks connected to a router make up a collision domain. All devices connected to a hub will also make one collision domain.
On a new switch, the switch learns the location of devices by examining the _________ IP address.
source
What is the role of distribution switches and how are they implemented?
Linked to each other via high-speed connections, connected to high-speed core switches, and constitute the second tier in a two-tier network design.
Describe core switches and how they are implemented.
They reduce the number of uplinks required to connect each building to the campus network, provide high speed connections between distribution switches and are not used in a two-tier (collapsed core) network design.
A Cisco switch out of the box is ______ on all its ports.
Live
What things should you configure on a cisco switch?
Passwords, IP address, default gateway
How would you configure the speed and duplex settings on a Cisco Switch?
enable configure interface range [ex. f0/1-24, f0/25-27] OR interface [name] speed [mb/auto] duplex [full/half/auto]
How do you administratively shutdown a port to prevent “plug and play” Switch connectivity on a port?
enable configure interface range OR interface shutdown
How do you enable or disable a switch interface?
no shutdown (enable) shutdown (disable)
How do you show interface status of all ports?
show interface status
How do you show line and protocol statuses of all ports?
show ip interface brief
A workstation is connected to a switch on the Gi0/2 interface using a straight-through cable. The Ethernet interface in the workstation has been manually configured to use a 100 Mbps link speed and full duplexing. What (3) things are true in this scenario?
(1) if the link speed is 1000 Mbps or faster full duplex is used
(2) If the link speed is 10 Mbps or 100 Mbps, half duplex is used
(3) The switch attempts to sense the link speed. If it can’t the slowest link speed supported on the interface is selected.
How do you configure a Switch’s default IP and gateway for the first time?
enable
show IP interface brief
conf t
interface vlan 1
ip address [address] [mask]
exit
ip default-gateway [address of next hop device]
exit
copy run startHow do you verify the current switch configuration?
show run
How do you see neighbor cisco devices?
show cdp neighbor (opt’l: detail)
To administer a switch remotely, what needs to be configured?
The switch must be configured with a valid IP address and default gateway, and the remote workstations must have access to the management VLAN of the switch
DNS name resolution looks for information in the following places in this order:
Local DNS cache
HOSTS file
DNS server query
What command do you use to configure DNS server addresses for the router to use for resolving host names?
ip name-server
What command do you use to create static entries for hosts, associating a host name with an IP address?
ip host
What command do you use to prevent the router from using DNS to resolve host names?
no ip domain-lookup
What command do you use to set the DNS name used by the router?
hostname
An amber system light on the switch means …
The system has power but is not functioning properly
If the port light flashes amber and green with the Stat mode selected…
the switch has detected errors such as CRC errors, excessive collisions, or a jabbering network card
