Test your basic knowledge |

CCNP Switch Deck

Instructions:

Answer 50 questions in 15 minutes.
If you are not ready to take this test, you can study here.
Match each statement with the correct term.
Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.

1. What is a service set?
Switch(config-if)# standby xx where x= group number
A group of wireless devices that share a common SSID
A router keeps a routing table and an ARP table. The FIB combines them for every next-hop entry
If a unidirectional link is detected - the switch doesn't try to reestablish the link. ULD msgs are sent once/sec for 8 seconds - then the port is err-disabled

2. What is the traditional MLS view of switching?
Hashing algorithm
2
When a specific interface is tracked - HSRP reduces it's priority after a specified interval.
Route once - switch many

3. What is the STP hello timer?
Time between BDPUs sent by root bridge. Default of 2 seconds
An instance of RSTP running for each VLAN on the switch. Changing from PVST to RPVST+ is disruptive
0-255
Can send and receive BDPUs

4. RSTP BPDU structure
Some unused bits are used to allow a port to identify its role and state. Also the BDPUs state that they are V2 BDPUs
That they aren't using the same frequencies.
By using a hash of a key string
MAC of the end device

5. What are the 4 steps in DHCP negotiation?
1-client sends DHCP discover as broadcast - 2-DHCP server sends DHCP offer - client sends DHCP Request - DHCP server sends DHCP ack
When the size of a cell is intentionally reduced
When the AP uplinks to an Ethernet network.
1- root bridge is elected - 2-the state of eery switch port in the STP domain must be brought from blocking state to the appropriate state

6. What happens if both 802.1D and RSTP BDPUs are received?
All user ports that have portfast enabled
Incoming frames are dropped (combination of disabled - blocking - and listening)
The port will operate under 802.1D rules. If they are received on the same port - it will run 802.1D until the migration delay expires
They shorten their bridge table aging times from default (300sec) to the fowarding delay (15 sec)

7. How far chould a VLAN extend?
300 sec by default
Root - designated - blocking - alternate - forwarding (host)
Distribution layer
Trunk - dynamic auto - dynamic desireable (default)

8. What is the LACP priority range?
Stateful switchover - redundant sup is fully booted and init'd. Both start and run config are synched as is L2 information - and switchinterfaces.
Untrusted
CEF is distributed across multiple L3 forwarding engines - typically on Catalyst 6500 line cards each having only a subset
1-65535 (def 32768) lower priority - higher probability

9. What is the bridge priority range?
The frame tag includes a 3 bit COS value from 0 (low) to 7 (high). Native vlans are untagged so no COS
Listens to the first packet going to router and away from the router. If it can switch in both directions - it learns a shortcut path so subsequent packets can be switched without the RP
To a VLAN and not to a VLAN interface (SVI)
0-65535 (def 32768) lower=better

10. What is the acceptible range of VLANS?
1-1005 (1 and 1002-1005 are reserved)
All L2 connectivity should be contained within the access layer.
Transmits keystrokes from phone and commands from CCM
Port that connects to another switch and becomes a designated port

11. At what layer should the WLC be connected?
Isolated and community
Distribution
Per-port or globally for all fiber-optic ports. Can be enabled globally - but will only affect fiber ports
L2

12. RSTP alternate port
If a unidirectional link is detected - the switch doesn't try to reestablish the link. ULD msgs are sent once/sec for 8 seconds - then the port is err-disabled
Port with alternative path to root less desirable than root
Enables switches at the end of the spanning tree branches to have a functioning root port while keeping 1 or more redundant potential ports in blocking mode. When the main fails - the other comes up.
Change in trunk encap

13. What types of authentication does HSRP allow?
Real-time functions such as beacons and probes - encryption and interactions with the client at L2
By brining up a tunnel between them to carry 802.11 related messages and client data.
Host Standby Router protocol. Cisco proprietary. Switch is either active - standby - or listen
Plain text or md5

14. What does DTP do?
Only a single host connects . If one BDPU is received - it is no longer an edge port
Incoming frames dropped - but MACs learned
Automatically negotiates a common trunk mode between switches
Within a single MST region - an IST instances runs to work out a loop free topology between links where CST meets the region boundary and all switches in the region. It runs at the boundary.

15. what should you do if you expect a PAgP capable switch at the other end vs. a server or host?
Only when a nonedge port transitions to forwarding
1 IP subnet
Forces the router to wait for a period of time before attempting overthrow
Configure non-silent submode

16. What are the steps to configure MST?
1- enable MST - 2-enter MST config mode - 3-assign region name and region configuration rev - 4-map vlans to an MSTI - 5-show pending changes - 6- commit by exiting
The standby becomes active and stays active by default. Preemption can be configured
0007.b4xx.xxyy where xx.xx is six 0 bits followed by a 10-bit GLBP group numberr. Yyyy is the virtual forwarder number
Data and voice over native vlan no QOS and no 802.1p trunk

17. What is the portr ID?
16 bits (8b port priority - 8b port number)
Within a single MST region - an IST instances runs to work out a loop free topology between links where CST meets the region boundary and all switches in the region. It runs at the boundary.
The ASIC
No shut

18. How do you prevent VLAN hopping?
Set the native VLAN of a trunk to a bogus or unused VLAN ID then prune the native VLAN off both ends of the trunk
Checks the source MAC in the header against the sender MAC in the ARP reply
On ports where you never expect to find a root bridge for a VLAN
Configure and enable DHCP snooping

19. where does L2 switching occur?
Root - designated - blocking - alternate - forwarding (host)
Between interfaces that are assigned to L2 VLANs or L2 trunks
Yes
Connects to a router - firewall - or gateway. Can communicate with anything else connected to the primary or any secondary. Ignores pvlan config

20. How are VACLs applied
Used to switch packets that can't be forwarded normallly due to an encapsulation failure - unresolved address - unsupported protocol - etc.
1 second. Backup routers can learn the interval from the master
To a VLAN and not to a VLAN interface (SVI)
1-LAP gets a DHCP address - 2-LAP learns IP of available WLC - 3-LAP sends a join request to WLC and receives join reply - 4-WLC sends code image - if necessary - 5-Tunnels are created

21. How does an L2 switch do QOS?
Switch(config-if)# standby xx where x= group number
Effectively stops STP on filtered ports
An L2 switch can only forward frames best effort unless going across a trunk
Forces the router to wait for a period of time after the switch is reloaded before attempting to overthrow

22. How does IPT behave when the voice VLAN is in untagged mode?
16 - of which up to 8 are active. The others are in standby
The port will operate under 802.1D rules. If they are received on the same port - it will run 802.1D until the migration delay expires
Data and voice over native vlan - no QOS but still uses 802.1p trunk
Route processor redundancy - redundant sup is partially booted and initialized and must reload module in the switch and init all sup functions

23. What scope is 802.1x enabled?
Weak key rotation
Globally
Used to switch packets destined for the null interface
Only for trusted Cisco gear - especially phones

24. what I s distributed CEF (dCEF)?
Time between BDPUs sent by root bridge. Default of 2 seconds
CEF is distributed completely among multiple L3 forwarding engines.
Normal and aggressive
An AP's coverage area

25. How is Root Guard used?
Distribution layer
From the DHCP snooping database or from static entries
On ports where you never expect to find a root bridge for a VLAN
Port is forced to never authorize any connected client

26. What are the port channel load balancing methods?
Src-ip - dst-ip - src-dst-ip - src-mac - dst-mac - src-dst-mac - src-port - dst-port - src-dst-port
Configure and enable DHCP snooping
Configuration and TCN
Trunk - dynamic auto - dynamic desireable (default)

27. What is layer 2 roaming?
300 sec by default
If the client maintains the same IP address as it roams between Aps. All must have same VLAN - SSID - and subnet
A TCN BDPU is sent out of the switch's root port. The switch will continue sending TCN's every hello interval until ack'd by upstream neighbor. The root bridge will send a Config BDPU to all switches
To a VLAN and not to a VLAN interface (SVI)

28. What is SSO?

Warning: Invalid argument supplied for foreach() in /var/www/html/basicversity.com/show_quiz.php on line 183

29. What is arp throttling?
0-65535 (def 32768) lower=better
During the time that the FIB entry is in CEF glean waiting for ARP entries - subsequent packet to that host are dropped to keep input queues from filling
1- enable MST - 2-enter MST config mode - 3-assign region name and region configuration rev - 4-map vlans to an MSTI - 5-show pending changes - 6- commit by exiting
If three are missed in a row - the neighbor is considered down and the data for that neighbor is aged

30. What is UDLD normal mode?
Using digital certificates
When a client roams between Aps in different subnets
If a unidirectional link is detected - the port continues normally - but the port is marked as undetermined and a syslog is generated
Access

31. How do Cisco IP phones communicate with the CCM?
With the skinny protocol
1-name the chain - 2-establish a key number - 3-create the key string - 4-apply the chain to the string
Incoming frames are dropped (combination of disabled - blocking - and listening)
Allows devices to interoperate with PVST and CST. Can use both dot1q and ISL

32. RSTP discarding state
All ports where root isn't expected
Incoming frames are dropped (combination of disabled - blocking - and listening)
Any ports associated with an isolated vlan can reach the primary - but not any other secondary. Hosts withn an isolated vlan can't reach each other
The distribution layer should have only L3 links

33. What is the GLBP redirect timer?
LACP port priority
Determines when the AVG will stop using the old VMAC in ARP replies
Low cost - high density ports - multiple scalable uplinks - vlans - traffic and protocol filtering and QoS
The frame tag contains a 3 but portion tagged from 0 (low) to 7 (high)

34. What is latency?
Missed beacons - dropped packets (max retry) - weak signal (data rate switches down) - an AP periodicallytries to find a stronger signal
The total delay from start to finish
If any BDUP is received on a port - it puts the port into the errdisable state
Multicast to 01-80-c2-00-00-00

35. What is dynamic desireable?
By using an Ether-IP tunnel
Plain text or md5
Gateway load balancing protocol - cisco proprietary
The port asks the other end to trunk

36. How many MST instances can be in a region?
Promiscuous and host
Root
A private VLAN can be logically associated with a special secondary vlan
16 - IST gets MSTI 0 - 1-15 are available for use. MSTIs are locally significant to the MST region

37. What is the PVLAN host mode?
Checks the destination MAC in the header against the target MAC in the ARP reply
Access or trunk
Globally
Connects to a host on an isolated or community vlan. Communicates only with promiscuous port or ports on same community vlan

38. One vlan should =
Because each frame is checked
5 classes with 3 drop precedences
All L2 connectivity should be contained within the access layer.
1 IP subnet

39. How do you renable an err-disable port by default?
Automatically using DTP and CDP
If a unidirectional link is detected - the switch doesn't try to reestablish the link. ULD msgs are sent once/sec for 8 seconds - then the port is err-disabled
Manually
On the left as you face the connector

40. What is a CEF glean?

Warning: Invalid argument supplied for foreach() in /var/www/html/basicversity.com/show_quiz.php on line 183

41. At what layer does EAPOL run?
L2
A point to point port type but the neighboring device runs traditional 802.1D STP
CEF is distributed completely among multiple L3 forwarding engines.
16 bits (8b port priority - 8b port number)

42. What is a null adjacency?
1 per segment
Used to switch packets destined for the null interface
Admin down
Data goes over native vlan - voice goes over VLAN0 - voice QOS is 802.1p

43. How much overlap should a wireless repeater have?
Roughly 50%
Root
63 kbps
Enables portfast - sets the port to access and disables PAgP

44. What does the dst-mac option do when checking ARP replies
It updates the L2 headers with the proper src and dst MAC - L3 TTL - L3 checksum - and L2 checksum information
Checks the destination MAC in the header against the target MAC in the ARP reply
1-ID link path costs - 2-ID roodt bridge - 3-select root port (1/switch) - 4-select designated port (1/segment) - 5-ID blocking port
Admin down

45. What is RPVST+?
Bridge priority and MAC
An instance of RSTP running for each VLAN on the switch. Changing from PVST to RPVST+ is disruptive
Trusted ports
When a client roams between Aps in different subnets

46. Can two switches in the auto(PAgP) or passive (LACP) mode create a channel? Why?
802.1D
No because they only participate if asked
To a VLAN and not to a VLAN interface (SVI)
Gateway load balancing protocol - cisco proprietary

47. What does BDPU filtering do?
Effectively stops STP on filtered ports
1-LAP gets a DHCP address - 2-LAP learns IP of available WLC - 3-LAP sends a join request to WLC and receives join reply - 4-WLC sends code image - if necessary - 5-Tunnels are created
1- enable qos - 2-define qos parameters to be trusted - 3-make trust conditional - 4-instruct IP phone how to extnd boundary
No because they only participate if asked

48. How does loop guard block ports?
300 sec
1-ID link path costs - 2-ID roodt bridge - 3-select root port (1/switch) - 4-select designated port (1/segment) - 5-ID blocking port
Only for the offending VLAN on the port
The number of times the entry has been updated since the table was generated

49. How often are HSRP hellos sent?
Route once - switch many
Sends special layer 2 UDLD frames and expects an echo. Both ends must be configured for UDLD
3 seconds. Holdtime =3 hellos + 1
Almost eliminates listening and learning states for single hosts on an access link

50. What does the minimum keyword do in HSRP?
Group (0-255) - priority (1-254 254 is highest - 100 default)
16 - IST gets MSTI 0 - 1-15 are available for use. MSTIs are locally significant to the MST region
The campus network's backbone
Forces the router to wait for a period of time before attempting overthrow