K Exam Review 1 Flashcards
Create an access list that denies traffic from network 10.10.10.0/24 but allows traffic from all other networks.
R1(config)#access-list 1 deny 10.10.10.0 0.0.0.255
R1(config)#access-list 1 permit any
What is the command to change mac addy aging time?
mac-address-table aging-time 400
What command will allow you to view the mac address table?
show mac address-table
Command that will allow you to display all connected ports on a switch?
show interfaces status
Commands for the three modes of DTP?
#switchport mode dynamic auto #switchport mode dynamic desirable #switchport mode nonegotiate
Show switchport and VLAN info for an interface.
show interface g0/1 switchport
What is the extended VLAN range?
1006 to 4094 - extended VLAN range
What is the normal VLAN range?
1 to 1001 - normal VLAN range
Range reserved for FDDI
Fiber Distrubution Data Interface - FDDI
is a standard for data transmission in a local area network. It uses optical fiber as its standard underlying physical medium.
Reserved - 1002 - 1005
List facts about Native VLANs
- Should be the same on both ends of the trunk.
- Useful with VOIP.
- Compatible with old switches that don’t trunk.
- Can’t be changed nor deleted.
- Useful when data and voice VLANs share the same link.
Commands to create an SVI.
SVI - logical interface that is associated with a VLAN.
#int vlan 17 #ip add 10.1.1.1 255.0.0.0
Command to set up a layer 3 switch for routing.
ip routing
Command to configure an interface for a newly created VLAN?
(config-if)#switchport access vlan 9
VOIP phone and computer is on the same interface. What command will allow the voip phone to switch traffic onto it’s vlan?
(config-if)# switchport voice vlan 4
Configure an interface with vlan ID 8 and let it support a voip phone on vlan 6.
(config-if)# switchport access vlan 8
(config-if)# switchport voice vlan 6
What happens when you configure a port to access mode?
When you configure a port to access mode it protects it from automatically trunking.
List three facts about CDP.
Cisco Discovery Protocol - CDP
- It is required for VOIP phones.
- It allows switch to learn capabilities of device
- It allows the switch to learn power requirements
What does the command #show interfaces switchport display?
show interfaces switchport displays:
- status
- vlan configured
- operational mode
What command will display all configured trunks on a switch including protocols?
show interfaces trunk
Display mode settings for VTP.
show vtp status
Remove vlans 2 to 4 from allowed list on a trunk interface.
(config-if)# switchport trunk allowed vlan remove 2-4
Reset to default allowed vlans on a trunk.
(config-if)# switchport trunk allowed vlan all
Add a vlan to an allowed list
(config-if)# switchport trunk allowed vlan add 4
Describe VTP transparent mode.
- Won’t participate in VTP
- Will receive and forward VTP advertisements
Describe VTP client mode.
- Allows switch to act as a slave to the master server.
Describe VTP Server mode.
- Default mode
- Allows the switch to act as a master for the VTP domain
What is VTP pruning and how do you enable it?
vtp pruning
VTP pruning helps improve bandwidth by reducing unnecessary flooded traffic, such as broadcast, multicast, unknown, and flooded unicast packets.
For example, if switch A does not have a port configured for VLAN 7, and broadcast is sent throughout VLAN 7, that broadcast or traffic will not pass through the trunk link to switch A.
VTP pruning should only be enabled on VTP servers, all the clients in the VTP domain will automatically enable VTP pruning.
By default, VLANs 2 – 1001 are pruning eligible, but VLAN 1 can’t be pruned because it’s an administrative VLAN. Both VTP versions 1 and 2 support pruning
Verify VTP configuration.
Switch# show vtp status | include Pruning
VTP Pruning Mode : Enabled
Command that turns off DTP.
(config-if)# switchport nonegotiate
Describe DTP
The Dynamic Trunking Protocol (DTP) is a layer 2 protocol used to negotiate forming a trunk between two Cisco devices. DTP causes increased traffic, and is enabled by default, but may be disabled.
What is the default DTP mode?
The default DTP mode is access.
Configure DTP on interface f0/1 for VLAN 5.
#int f0/1 #switchport mode access #switchport access vlan 5
2 show commands that will show detailed information about a trunk.
#show interfaces trunk more info #show interfaces switchport
Show trunking information for a single interface?
show interfaces fa0/5 switchport
Describe 802.1x.
Security protocol used per port to allow or deny traffic based on credentials.
802.1Q - How many bytes are used for tagging
4 bytes are used for 802.1q tagging.
Command to show native vlan for an interface.
show interface fa0/15 switchport
Command to change native vlan for an interface.
(config-if)#switchport trunk native vlan 999
All ethernet traffic must be on what range of vlans
1-1001
Describe and provide the IEEE standard for LLDP
802.1ab - Link Layer Discovery Protocol collects info from neighboring devices about their identity and capabilities.
CDP does the same thing.
What commands would you use to turn off CDP?
#no cdp run (config-if)#no cdp enable
By default cdp advertisment frames are sent out how often?
60 seconds
What is the CDP default holddown timer?
180 seconds.
LLDP default advertisement interval is?
30 seconds
LLDP default holddown timer is?
120 seconds
Describe CDP hold time.
These packets advertise a time-to-live (TTL) value in seconds, which indicates the number of seconds that the packet must be retained before it can be discarded (default value is 180 seconds).
The amount of time before a router will discard information about another router if it doesn’t receive an advertisement frame.
Command that will show cdp neighbors with detail.
#show cdp neighbors detail #show cdp entry
How would you change cdp timers.
# configure terminal #cdp timer 5 #holdtime 100
Show cdp enabled interfaces
show cdp interface
