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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 LACP priority?
5 (0-4 with 4 being the highest)
Routers at the distribution layer become the bottlenecks or broadcast or multicast traffic slows the switches in the switch block
L2
The priority is a 2 byte value followed by the MAC that decides which ports are actively participating in Etherchannel (lower=higher priority)

2. What is dynamic auto?
Every hello interval regardless of whether BDPUs are received from root - allowing any switch to take an active role maintaining the topology
Will trunk if asked
Regions and instances
224.0.0.2 (all routers)

3. What is unique about HSRP group numbers?
Src-dst-ip
They are locally significant on an interface. HSRP1 on one VLAN is different from HSRP1 on another
Routers at the distribution layer become the bottlenecks or broadcast or multicast traffic slows the switches in the switch block
Should be used on access switches - can't be used on root - keeps enabled switch from becoming root by raising priority of switch and all ports - making them undesirable

4. What does uplinkfast do?
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.
Cisco ILP and 802.3af
On by default
Both layer 2 switching and IVR

5. What is RTP?
Traffic types and patterns - amount of L3 switching cap. At dist. Layer - # users at access layer - geography - size of spanning tree domains
2
Data goes over native vlan - voice goes over VLAN0 - voice QOS is 802.1p
Real-time Transport Protocol

6. How is an RSTP edge port configured
With portfast
1-1005 (1 and 1002-1005 are reserved)
The time that a port spends in both listening and learning states . Default 15 seconds
Source IP and MAC must match those addresses learned by DHCP snooping or a static entry

7. What is the STP Max Age timer?
Globally or per-port
The time interval that a switch stores a DBPU before discarding it. Default 20 seconds
CEF is distributed completely among multiple L3 forwarding engines.
Src-ip - dst-ip - src-dst-ip - src-mac - dst-mac - src-dst-mac - src-port - dst-port - src-dst-port

8. What is the VRRP skew time?
Both layer 2 switching and IVR
Hold time is 3xhello. A skew time of 256ms-routerpriority)/256ms is added
The link status stays up - but something between them has failed or is filtering traffic
Very high L3 throughput - no access lists or port filtering - redundancy and resilience - advanced QoS

9. If you want IP source guard to detect spoofed MAC addresses - what must you do?
A single broadcast domain
Real-time Transport Protocol
Turn on port security
Will trunk if asked

10. How does IPT behave when the voce VLAN is in the default none mode?
Globally
Data and voice over native vlan no QOS and no 802.1p trunk
1-1005 (1 and 1002-1005 are reserved)
Normal and aggressive

11. What does Loop Guard do?
2-8 FE - GE - or 10GE are bundled.
Tracks of BDPUs on nondesignated ports. When those BDPUs stop coming - the port is put into loop-inconsistent state and blocks
1 per segment
No

12. WPA2 encryption
134 bits - consisting of source and destination addresses and protocol information from the packet or frame
1 IP subnet
An L2 switch can only forward frames best effort unless going across a trunk
Needs hardware upgrade over WEP - uses AES encryption

13. What is best effort delivery QOS?
Untrusted
FE - GE - and aggregated FE/GE Etherchannels
Switches make an effort to move packets as quickly as possible
Access

14. the static port to vlan membership is handled in _____
The port uses 802.1x exchange to move from unauthorized to authorized. Requires app on client
The master router can share the VIP
The ASIC
Sends a voltage across the receive pairs to detect a 25k ohm resistance

15. How do you configure a DHCP gateway?
Port is forced to never authorize any connected client
Effectively stops STP on filtered ports
Using digital certificates
First configure a L3 interface in same VLAN as clients - then use the ip helper-address command to ID the DHCP server

16. What are the 3 trunk encap modes?
Because each frame is checked
Interim solution - uses same hardware as WEP - but uses TKIP encryption
Isl - dot1q - negotiate (default)
FE and GE

17. What is the default 10mbps Enet duplex?
The wireless clients communicate directly with no other means of connectivity such as a WAP
All L2 connectivity should be contained within the access layer.
Half-duplex
Needs hardware upgrade over WEP - uses AES encryption

18. 802.11b
1 -2 -5.5 and 11 Mbps - Channels 1/6/11 - 2.4Ghz
3 seconds. Holdtime =3 hellos + 1
10-15%
Route once - switch many

19. What is NSF?
Multicast to 01-80-c2-00-00-00
Nonstop forwarding is an interactive method focusing on rebuilding the RIB after SUP switchover
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
Aggregation - high L3 throughput - security and policy based connectivity functions through access lists and packet filters - QoS - scalable high-speed links

20. What is a PVLAN?
For hosts that doesn't understand routing - the DGW is configured to reply with its own mac
0-65535 (def 32768) lower=better
A private VLAN can be logically associated with a special secondary vlan
No

21. What is a null adjacency?
Used to switch packets destined for the null interface
Isl - dot1q - negotiate (default)
All nondesignated ports - but ok for all ports
Each network device handles packets individually with no advance reservations

22. What are the 3 redundant supervisor modes?
Data and voice over native vlan no QOS and no 802.1p trunk
Root
RPR - RPR+ - and SSO
Packets must be sent to the L3 engine for further processing

23. How much overlap should WAPs have?
1-(opt) set system priority - 2-select interface(s) - 3-assign the protocol - 4-set the mode - 5-(opt) set the port priority
Those that connect to other switches
10-15%
Auto mode

24. Automatically configure STP timers
Use the spanning-tree root macro
Feature Manager - after the ACL is created - the FM compiles the ACEs into the table
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
Port stays up - but packets from violating MACs are dropped. Switch logs violating packets

25. What does the src-mac option do when checking ARP replies
Real-time Transport Protocol
The switch adds its MAC to the option 82 field so that the DHCP reply echoes back the switch's own information
Checks the source MAC in the header against the sender MAC in the ARP reply
The TOS field in the header is used. 2 methods 3 bits or 6 bits

26. What does the SP do?
Change in trunk encap
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
Each peer sends and receives hellos. Def hello is 3 sec - def hold is 10 sec
A MAC is seen on a different port

27. What is the core block?

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28. What is the size of ISL encapsulation?
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
Some unused bits are used to allow a port to identify its role and state. Also the BDPUs state that they are V2 BDPUs
Control functions
26-byte header - 4-byte trailer with CRC

29. 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
2
Access or trunk
Hold time is 3xhello. A skew time of 256ms-routerpriority)/256ms is added

30. How do IP phones communicate with each other?
Backbonefast uses RLQ to determine if upstream switches have stable connections to root bridge
Src-dst-ip
Once the CCM gives them the parameters - they use RTP
From the DHCP snooping database or from static entries

31. How does the VRRP master router handle the VIP?
2
Connects with SONET or SDH
The master router can share the VIP
Can hear only BDPUs

32. What is common spanning tree (CST)?
MST attributes must be manually entereed on each switch in the region. They don' t propagate like VTP.
Single instance of STP for all VLANs. BDPUs are sent over trunks using the native VLAN with untagged frames. Dot1q based
An ac adaptor that plugs into a wall outlet.
Can hear only BDPUs

33. What are the 2 UDLD modes?
Some unused bits are used to allow a port to identify its role and state. Also the BDPUs state that they are V2 BDPUs
A VLAN that spans the entire fabric
Flash (class 3)
Normal and aggressive

34. What if RSTP BDPUs aren't received?
If three are missed in a row - the neighbor is considered down and the data for that neighbor is aged
Switching Database Manager - configures and prunes TCAM partitions
Switched Virtual Interface - an L3 address can be assigned to a logical interface that represents an entire VLAN - which becomes the DGW for that VLAN
1 to 64

35. When should CDP be enabled?
Only for trusted Cisco gear - especially phones
LACP port priority
Data and voice over native vlan - no QOS but still uses 802.1p trunk
1 -2 -5.5 and 11 Mbps - Channels 1/6/11 - 2.4Ghz

36. What is the duration time in a wireless frame?
1 per segment
Each frame transmits its expected duration time
L2
Half-duplex

37. 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
By encapsulating each frame in a header and trailer
Completed dhcp bindings - mac addresses - IP addresses - etc.
Enables portfast - sets the port to access and disables PAgP

38. What feedback mechanism does wireless use?
Up to 54Mbps - not cross-compatible - 12 to 23 clean channels - 5.8 Ghz
When a wireless station transmits a frame - the receiving one must send an ack
Access or trunk
Yes

39. What does BDPU filtering do?
Real-time Transport Protocol
Immediate (class 2)
RADIUS
Effectively stops STP on filtered ports

40. What is dynamic desireable?
802.1x with EAP over LAN (EAPOL)
Very high L3 throughput - no access lists or port filtering - redundancy and resilience - advanced QoS
The port asks the other end to trunk
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

41. What's the easiest way to configure GLBP timers?
Any dhcp reply coming from an untrusted port is discarded and the offending port is put in errdisable
All nondesignated ports - but ok for all ports
Configure the timer on the AVG and let it propagate
Turn on port security

42. How does DSCP handle IP precedence?
5 classes with 3 drop precedences
A VLAN that spans the entire fabric
When a wireless station transmits a frame - the receiving one must send an ack
Two distribution switches that aggregate one or more access switches

43. What is DSCP codepoint EF(46)?
The number of times the CEF table has bee flushed and regenerated as a whole
Roughly 2000
Immediate (class 2)
Critical...used most often for IPT

44. What contains the next-hop entries?
5 (0-4 with 4 being the highest)
Only for trusted Cisco gear - especially phones
FIB
Protects STP when a physical malfunction only allows traffic in 1 direction - even though the link shows as up (cisco proprietary)

45. What does the standby HSRP router do?
Only the standby monitors the hello messages from the active router
1 -2 -5.5 and 11 Mbps - Channels 1/6/11 - 2.4Ghz
Isolated and community
Admin down

46. What are the 6 HSRP states?
Both layer 2 switching and IVR
Disabled - init - listen - speak - standby - active
Option 43
They should be an unconditional Etherchannel because the WLC can't negotiate a channel.

47. How do you configure IP source guard for hosts that don't use DHCP?
Show standby
Causes switch to actively determine whether alternative paths exist to root bridge in case ther eis an indirect failure
802.1w
By creating a static IP binding

48. How are errdisable triggers tuned?
Automatically by duplex mode in use. Full duplex are point ot point. Half duplex ports use traditional 802.1D convergence is used.
Based on priority (0-255). Default is 100. Highest IP is tie breaker
5 (0-4 with 4 being the highest)
Globally

49. What does MSTP do?
16 bits (8b port priority - 8b port number)
Hashing algorithm
Used when there are 1 or more VLANs mapped to a single STP instance
Should be used on access switches - can't be used on root - keeps enabled switch from becoming root by raising priority of switch and all ports - making them undesirable

50. What is an autonomous mode AP?
Port stays up - packets from violating MACs dropped - no logging
When each AP stands alone within the larger network.
The standby becomes active and stays active by default. Preemption can be configured
Checks the sender's ip in all arp requests and checks the sender's IP against target IP in all replies