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. RSTP root port
Very high L3 throughput - no access lists or port filtering - redundancy and resilience - advanced QoS
Access or trunk
Distribution layer
Port with best root path cost


2. What is a direct topology change?
One that can be detected on a switch interface (ie. Up/down)
Priority (class 1)
1-enable AAA on switch - 2-define RADIUS servers - 3-define authentication method - 4-enable 802.1x on switch - 5-conf. 802.1x ports - 6-allow hosts
The standby becomes active and stays active by default. Preemption can be configured


3. What are the 5 STP port roles?
Globally
Root - designated - blocking - alternate - forwarding (host)
The same as a standby group in HSRP
Usually QoS from VOIP but not PC dataa


4. WPA encryption
Group (0-1023) priority (1-255 higher better def 100)
LWAPP (Cisco proprietary) and CAP-WAP (standards based)
Interim solution - uses same hardware as WEP - but uses TKIP encryption
Bridge priority and MAC


5. What is step 1 of enabling IP source guard?
Silent
Access
Configure and enable DHCP snooping
Cisco ILP and 802.3af


6. Define HSRP
Host Standby Router protocol. Cisco proprietary. Switch is either active - standby - or listen
Gateway load balancing protocol - cisco proprietary
CEF is distributed across multiple L3 forwarding engines - typically on Catalyst 6500 line cards each having only a subset
Create 2 hsrp groups - each with the active router being different switches - then have clients point to each


7. What scope is 802.1x enabled?
Globally
When the size of a cell is intentionally reduced
Matching SSID - compatible data rate - authentication credentials
On the left as you face the connector


8. How are VACLs applied
Root
To a VLAN and not to a VLAN interface (SVI)
Via an 802.1Q trunk or a single VLAN access port
Cisco proprietary. 1 instance of STP/VLAN. Requires ISL instead of dot1q


9. What is the format of the VRRP virtual MAC?
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
0-255
Yes
0000.5e00.01xx


10. What is DAI?
On the left as you face the connector
Dynamic arp inspection
If three are missed in a row - the neighbor is considered down and the data for that neighbor is aged
1-1005 (1 and 1002-1005 are reserved)


11. What is a CEF glean?


12. What does the src-mac option do when checking ARP replies
All user ports that have portfast enabled
Checks the source MAC in the header against the sender MAC in the ARP reply
Very high L3 throughput - no access lists or port filtering - redundancy and resilience - advanced QoS
By sending a gratuitous ARP


13. How is RSTP synchronization accomplished?
26-byte header - 4-byte trailer with CRC
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
1-name the chain - 2-establish a key number - 3-create the key string - 4-apply the chain to the string
All non-edge ports are discarding. After the root bridge is identified - the port with superior BDPU becomes root


14. What is RPR+?


15. What is a null adjacency?
Those that connect to other switches
Used to switch packets destined for the null interface
Globally
PAgP (Cisco proprietary) and LACP (standards-based)


16. What is Per VLAN STP (PVST)?
Forces the router to wait for a period of time before attempting overthrow
Cisco proprietary. 1 instance of STP/VLAN. Requires ISL instead of dot1q
The DCF interframe space- the random backoff time before a wireless set can transmit
No because they only participate if asked


17. static vlans offer ____ based membership
Can send and receive BDPUs
The L3 forwarding engine can't forward the packet in hardware because there is no L2 next-hop address - so the packet is sent to the L3 engine to generate the ARP response
Port
Use the spanning-tree root macro


18. What is an autonomous mode AP?
The point at which a switch decides to trust incoming Qos. Usually at boundary with ISP
When each AP stands alone within the larger network.
It's a router that maintains routes (static or dynamic) - and populates the FIB
16 - of which up to 8 are active. The others are in standby


19. How many MST instances can be in a region?
Flash (class 3)
Switches make an effort to move packets as quickly as possible
16 - IST gets MSTI 0 - 1-15 are available for use. MSTIs are locally significant to the MST region
The station must wait until the frame in progress has completed - then wait a random amount of time before transmitting


20. What is the default 10mbps Enet duplex?
Half-duplex
Differentiated services code point
Root - designated - blocking - alternate - forwarding (host)
Aggregation - high L3 throughput - security and policy based connectivity functions through access lists and packet filters - QoS - scalable high-speed links


21. What does the switchport host macro do?
Sets the switchport mode to access - enables portfast - and turns off channel grouping for the port
A host port goes up or down
0-255
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


22. What does UDLD do?
Priority (class 1)
Protects STP when a physical malfunction only allows traffic in 1 direction - even though the link shows as up (cisco proprietary)
Matching SSID - compatible data rate - authentication credentials
Data goes over native vlan - voice goes over specified VLAN - voice QOS is 802.1p


23. What does the epoch number indicate when looking at cef entries?
1-(opt) configure load balancing - 2-select the interface(s) - 3-assign the protocol - 4-select the mode and submode
Admin down
Half-duplex
The number of times the CEF table has bee flushed and regenerated as a whole


24. How does HSRP port tracking work?


25. How does a DHCP server send WLC addresses?
134 bits - consisting of source and destination addresses and protocol information from the packet or frame
The switch checks the MAC and IP reported in the reply against trusted values. If they don't match - it is dropped and logged
No
Option 43


26. What is the STP forwarding state?
Yes to both
After another forwarding delay - the port can send and receive data frames - collect MAC addresses - and send and receove BDPUs
If the client maintains the same IP address as it roams between Aps. All must have same VLAN - SSID - and subnet
When the size of a cell is intentionally reduced


27. What is DSCP codepoint EF(46)?
Critical...used most often for IPT
Per-port or globally for all fiber-optic ports. Can be enabled globally - but will only affect fiber ports
Multicasts to 224.0.0.18 (VRRP)
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


28. What are the restrictions for bundling into an Etherchannel?
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
Trunk
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
Must be same type - speed - VLAN(s) - native vlan - pass the same set of vlans -duplex - and spanning tree settings


29. What contains the next-hop entries?
Sends special layer 2 UDLD frames and expects an echo. Both ends must be configured for UDLD
That they aren't using the same frequencies.
FIB
Both ends should be on because on modes doesn't send PAgP or LACP packets


30. What is RPR?
Globally
Multicasts to 224.0.0.18 (VRRP)
Route processor redundancy - redundant sup is partially booted and initialized and must reload module in the switch and init all sup functions
Critical...used most often for IPT


31. What is a root link query (RLQ)?
Backbonefast uses RLQ to determine if upstream switches have stable connections to root bridge
16 - of which up to 8 are active. The others are in standby
Src-dst-ip
Globally


32. What is errdisable dtp-flap?
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
1-65535 (def 32768) lower priority - higher probability
Change in trunk encap
Both layer 2 switching and IVR


33. What is the STP forward delay timer?
The time that a port spends in both listening and learning states . Default 15 seconds
Root - designated - blocking - alternate - forwarding (host)
Automatically by duplex mode in use. Full duplex are point ot point. Half duplex ports use traditional 802.1D convergence is used.
After another forwarding delay - the port can send and receive data frames - collect MAC addresses - and send and receove BDPUs


34. How are errdisable triggers tuned?
Globally
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
900 MHz - 2.4Ghz - and 5-6GHz
FE - GE - and aggregated FE/GE Etherchannels


35. What is DSCP codepoint AF11(10)?
L2
Priority (class 1)
Usually QoS from VOIP but not PC dataa
After another forwarding delay - the port can send and receive data frames - collect MAC addresses - and send and receove BDPUs


36. What can cause a wireless client to switch between Aps?
Can send and receive BDPUs
It updates the L2 headers with the proper src and dst MAC - L3 TTL - L3 checksum - and L2 checksum information
Silent
Missed beacons - dropped packets (max retry) - weak signal (data rate switches down) - an AP periodicallytries to find a stronger signal


37. For QoS - switch uplinks should always be considered as ____ _____?
From the DHCP snooping database or from static entries
1- trunking mode - 2-trunk encapsulation - 3-native VLAN - 4-allowed VLAN
Can send and receive BDPUs
Trusted ports


38. What is the default network diameter?
0-65535 (def 32768) lower=better
7 switches from root bridge
A private VLAN can be logically associated with a special secondary vlan
TCAM


39. What is the adjacency table?
Data and voice over native vlan - no QOS but still uses 802.1p trunk
A router keeps a routing table and an ARP table. The FIB combines them for every next-hop entry
L2
By an ARP access list that defines the permitted bindings


40. What is the port priority range?
Port with alternative path to root less desirable than root
It can't
0-255 (lower is better)
To a VLAN and not to a VLAN interface (SVI)


41. What happens during HSRP failover?
Protects STP when a physical malfunction only allows traffic in 1 direction - even though the link shows as up (cisco proprietary)
Automatically by duplex mode in use. Full duplex are point ot point. Half duplex ports use traditional 802.1D convergence is used.
Almost eliminates listening and learning states for single hosts on an access link
The standby becomes active and stays active by default. Preemption can be configured


42. What is a topology change?
It's a router that maintains routes (static or dynamic) - and populates the FIB
When a port moves into forwarding or from fowarding or learning to blocking.
0-255
Disabled - blocking - listening - learning - forwarding


43. What is a wall wart?
Packets must be sent to the L3 engine for further processing
Automatically by duplex mode in use. Full duplex are point ot point. Half duplex ports use traditional 802.1D convergence is used.
An ac adaptor that plugs into a wall outlet.
Used when there are 1 or more VLANs mapped to a single STP instance


44. What are the 2 UDLD modes?
2 strand MMF with MT-RJ or SC connectors
Normal and aggressive
26-byte header - 4-byte trailer with CRC
PAgP (Cisco proprietary) and LACP (standards-based)


45. WEP encryption
VTP server for domain null with no password or secure mode
Weak key rotation
Connects with SONET or SDH
1-65535 (def 32768) lower priority - higher probability


46. Which 4 things must be agreeable to trunk?
Trunk - dynamic auto - dynamic desireable (default)
1-client sends DHCP discover as broadcast - 2-DHCP server sends DHCP offer - client sends DHCP Request - DHCP server sends DHCP ack
When a specific interface is tracked - HSRP reduces it's priority after a specified interval.
1- trunking mode - 2-trunk encapsulation - 3-native VLAN - 4-allowed VLAN


47. What is backbonefast?
Feature Manager - after the ACL is created - the FM compiles the ACEs into the table
Causes switch to actively determine whether alternative paths exist to root bridge in case ther eis an indirect failure
Only on ports that have same static VLANs or trunking. It also modifies parameters of the channel if one of the ports is modified
Almost eliminates listening and learning states for single hosts on an access link


48. What can the Etherchannel hash use?
A path is pre-arranged for priority along the complete path from source to destination using the RSVP protocol.
They disguise the origin of an attack
Source IP - dest IP - combination of source and dest IP - source and dest MAC - or TCP/UDP port numbers
1 per segment


49. How many tunnels exist between the LAP and WLC?
An L2 switch can only forward frames best effort unless going across a trunk
2 - one for control messages and one for data
The port is forced to always authorize any connected client with no authentication necessary (default)
Packets must be sent to the L3 engine for further processing


50. How does ISL do trunking?
By encapsulating each frame in a header and trailer
Global config (vlan - vtp mode - and vtp domain) and VLAN DB mode commands. Global config is preferred because VLAN DB mode commands are legacy
A single broadcast domain
Admin down