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 data does DHCP snooping track?
Completed dhcp bindings - mac addresses - IP addresses - etc.
The distribution layer should have only L3 links
After forwarding delay - port can learn new MAC addresses
19


2. What is the default VTP state?
The total delay from start to finish
When a port moves into forwarding or from fowarding or learning to blocking.
Globally
VTP server for domain null with no password or secure mode


3. What is the STP disabled state?
Configuration and TCN
Completed dhcp bindings - mac addresses - IP addresses - etc.
63 kbps
Admin down


4. What does a LAP do if it loses communication with it's WLC?
A port can only forward or relay BDPUs - but can't receive them - disabled by default - enabled per-port - blocks port when superior BDPUs are received
Only on ports that have same static VLANs or trunking. It also modifies parameters of the channel if one of the ports is modified
Reboots and searches for a new WLC
1-lowest root bridge ID - 2-lowest root path cost - 3-lowest bridgeID - 4-lowest port ID


5. What does the skinny protocol do?
Bridge priority and MAC
All user ports that have portfast enabled
Yes
Transmits keystrokes from phone and commands from CCM


6. How are RSTP point to point ports determined?
Automatically by duplex mode in use. Full duplex are point ot point. Half duplex ports use traditional 802.1D convergence is used.
Up to 54Mbps - not cross-compatible - 12 to 23 clean channels - 5.8 Ghz
When a specific interface is tracked - HSRP reduces it's priority after a specified interval.
Once the CCM gives them the parameters - they use RTP


7. How can you tell if a switch block is too large?
Routers at the distribution layer become the bottlenecks or broadcast or multicast traffic slows the switches in the switch block
1 IP subnet
Transmits keystrokes from phone and commands from CCM
The port uses 802.1x exchange to move from unauthorized to authorized. Requires app on client


8. What is the portr ID?
16 bits (8b port priority - 8b port number)
Incoming frames are dropped (combination of disabled - blocking - and listening)
The wireless clients communicate directly with no other means of connectivity such as a WAP
Collision domain


9. If a wireless station needs to transmit and another device is transmitting - what happens?
Cisco ILP and 802.3af
Feature Manager - after the ACL is created - the FM compiles the ACEs into the table
All ports where root isn't expected
The station must wait until the frame in progress has completed - then wait a random amount of time before transmitting


10. What happens when switches receive a configuration BDPU?
Group (0-255) - priority (1-254 254 is highest - 100 default)
Causes switch to actively determine whether alternative paths exist to root bridge in case ther eis an indirect failure
They shorten their bridge table aging times from default (300sec) to the fowarding delay (15 sec)
Globally or per-port


11. How do you show HSRP status
Global config (vlan - vtp mode - and vtp domain) and VLAN DB mode commands. Global config is preferred because VLAN DB mode commands are legacy
Port stays up - but packets from violating MACs are dropped. Switch logs violating packets
Data and voice over native vlan - no QOS but still uses 802.1p trunk
Show standby


12. What are the 3 ways GLBP load-balances?
1 second. Backup routers can learn the interval from the master
Round robin - weighted - or host-dependent
When a port moves into forwarding or from fowarding or learning to blocking.
Globally


13. What is DSCP codepoint AF11(10)?
Trunk
7 switches from root bridge
If a unidirectional link is detected - the port continues normally - but the port is marked as undetermined and a syslog is generated
Priority (class 1)


14. How much overlap should a wireless repeater have?
Roughly 50%
The wireless clients communicate directly with no other means of connectivity such as a WAP
To the virtual port-channel interface
If the client maintains the same IP address as it roams between Aps. All must have same VLAN - SSID - and subnet


15. How is RSTP synchronization accomplished?
Once the CCM gives them the parameters - they use RTP
A single broadcast domain
All non-edge ports are discarding. After the root bridge is identified - the port with superior BDPU becomes root
Dynamic arp inspection


16. How does HSRP election work?
Based on priority (0-255). Default is 100. Highest IP is tie breaker
Only for the offending VLAN on the port
Roughly 50%
The time interval that a switch stores a DBPU before discarding it. Default 20 seconds


17. What happens when an ARP reply is received on an untrusted port?

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18. How do VRRP routers handle preemption?
1- trunking mode - 2-trunk encapsulation - 3-native VLAN - 4-allowed VLAN
One router is the active virtual gateway - has highest priority or IP in group - answers all ARP requests and gives MAC based on load balancing
Switch(config-if)# vrrp xx where xx= group number
On by default


19. What is an autonomous mode AP?
Distribution layer
When each AP stands alone within the larger network.
Used when ACLs specify port ranges...used by TCAM
Allows devices to interoperate with PVST and CST. Can use both dot1q and ISL


20. How long are TCAM masks?
134 bits
Configure non-silent submode
When a port moves into forwarding or from fowarding or learning to blocking.
Critical...used most often for IPT


21. Of what significance are private VLANs
Configure and enable DHCP snooping
Local only
Sends a test tone on the transmit pair. If a device is detected - CDP is used to narrow down the power class.
They should be an unconditional Etherchannel because the WLC can't negotiate a channel.


22. How does L3 QOS classification happen?
The TOS field in the header is used. 2 methods 3 bits or 6 bits
10-15%
By sending a gratuitous ARP
Option 43


23. Where does VRRP send advertisements?
802.1x with EAP over LAN (EAPOL)
Multicasts to 224.0.0.18 (VRRP)
It can't
Trusted or untrusted


24. What is the IEEE standard for STP?
MAC addresses are learned from the source MAC of incoming frames. If the destination address is unknown - the frame is flooded out all except the receiving port.
802.1D
Using a single WAP to centralize access and control over a group of wireless devices.
Two distribution switches that aggregate one or more access switches


25. What is the duration time in a wireless frame?
802.1x with EAP over LAN (EAPOL)
0-255
Each frame transmits its expected duration time
1 to 64


26. How much overlap should WAPs have?
If three are missed in a row - the neighbor is considered down and the data for that neighbor is aged
Turn on port security
They are locally significant on an interface. HSRP1 on one VLAN is different from HSRP1 on another
10-15%


27. what must be done on an SVI before it is activated?
No shut
MAC of the end device
An instance of RSTP running for each VLAN on the switch. Changing from PVST to RPVST+ is disruptive
All ARP packets that arrive on untrusted ports are inspected.


28. WPA2 encryption
1 to 64
The master router can share the VIP
Needs hardware upgrade over WEP - uses AES encryption
To a VLAN and not to a VLAN interface (SVI)


29. What is jitter?
The active router. All other routers are in backup state
Variation in delay
Sends special layer 2 UDLD frames and expects an echo. Both ends must be configured for UDLD
16 bits (8b port priority - 8b port number)


30. How many users should be within a switch block?
Only for trusted Cisco gear - especially phones
Roughly 2000
Used to switch packets that can't be forwarded normallly due to an encapsulation failure - unresolved address - unsupported protocol - etc.
Frames are forwarded


31. What is the STP learning state?
No
Packets must be sent to the L3 engine for further processing
After forwarding delay - port can learn new MAC addresses
After another forwarding delay - the port can send and receive data frames - collect MAC addresses - and send and receove BDPUs


32. What is a wall wart?
The configureable UDLD interval must be less than max age plus two intervals of forward delay
An ac adaptor that plugs into a wall outlet.
Globally
All nondesignated ports - but ok for all ports


33. What is a null adjacency?
Used to switch packets destined for the null interface
Limits the number if dhcp requests on a port
Frames are forwarded
Can hear only BDPUs


34. How is DHCP snooping enabled (scope)?
1 -2 -5.5 and 11 Mbps - Channels 1/6/11 - 2.4Ghz
Almost eliminates listening and learning states for single hosts on an access link
By encapsulating each frame in a header and trailer
Globally


35. What is a VRRP group?
0000.0c07.acxx where xx is the group number as a 2-digit hex value
The port asks the other end to trunk
After forwarding delay - port can learn new MAC addresses
The same as a standby group in HSRP


36. What does the SP do?
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
By sending a gratuitous ARP
MST attributes must be manually entereed on each switch in the region. They don' t propagate like VTP.
Yes to both


37. How is an RSTP edge port configured
Sends special layer 2 UDLD frames and expects an echo. Both ends must be configured for UDLD
With portfast
2
Show standby


38. Where is the QoS trust boundary usually configured on an IP phone?
Best effort delivery - integrated services model - and differentiated services model
Usually QoS from VOIP but not PC dataa
Data and voice over native vlan - no QOS but still uses 802.1p trunk
Disabled - blocking - listening - learning - forwarding


39. What is route caching?

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40. If the WLC connects to an Etherchannel - how should the channel be configured and why?

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41. What is the cost of a 100Mbps link?
Arp for local subnet - if on different subnet - will arp for dgw
Root
19
Determines when the AVG will stop using the old VMAC in ARP replies


42. What is a cell?

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43. How is an instance defined?
Auto mode
By name - config revision - and instance to vlan mapping table
Compatible with 802.11b - up to 54Mbps in 12 data rates - 3 channels - 2.4Ghz
Lowest cumulative cost to root


44. 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
By encapsulating each frame in a header and trailer
Only for trusted Cisco gear - especially phones
Manages addition - deletion and renaming VLANs across the network


45. How does an L2 switch do QOS?
The distribution layer should have only L3 links
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
Promiscuous and host
An L2 switch can only forward frames best effort unless going across a trunk


46. What is a proxy arp?

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47. What is a vlan?
Either desirable or auto mode
0-255 (lower is better)
A single broadcast domain
The port asks the other end to trunk


48. How do IP phones communicate with each other?
Once the CCM gives them the parameters - they use RTP
As a VLAN access map
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
Half-duplex


49. What does the epoch number indicate when looking at cef entries?
No
The campus network's backbone
The number of times the CEF table has bee flushed and regenerated as a whole
A single broadcast domain


50. What is a microcell?
Half-duplex
5 classes with 3 drop precedences
When the size of a cell is intentionally reduced
When a client roams between Aps in different subnets