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. How is DHCP snooping enabled (scope)?
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
Globally
Port with redundant - but less deisrable connection to a segment. Possibly root candidate
Each physical interface has a different IP address. All physical interfaces point to a virtual interface called the standby address or VIP


2. What is DSCP codepoint AF11(10)?
802.1D
Connects with SONET or SDH
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
Priority (class 1)


3. What is the STP disabled state?
The wireless clients communicate directly with no other means of connectivity such as a WAP
Admin down
Only for the offending VLAN on the port
Port stays up - but packets from violating MACs are dropped. Switch logs violating packets


4. Where does layer switching occur?
Sends special layer 2 UDLD frames and expects an echo. Both ends must be configured for UDLD
The switch adds its MAC to the option 82 field so that the DHCP reply echoes back the switch's own information
Between interfaces that are assigned to L2 VLANs or L2 trunks
Between any type of interface as long as the interface can have an L3 address assigned


5. What functions does a WLC perform?
1500B
Only for the offending VLAN on the port
Globally
Control functions


6. what should you do if you expect a PAgP capable switch at the other end vs. a server or host?
Configure non-silent submode
Roughly 2000
Differentiated services
Globally


7. How many tunnels exist between the LAP and WLC?
Each physical interface has a different IP address. All physical interfaces point to a virtual interface called the standby address or VIP
2 - one for control messages and one for data
The topology is pre-populated by downloading the topology DB into the FIB and dynamically updated. Called Cisco Express Forwarding
They are locally significant on an interface. HSRP1 on one VLAN is different from HSRP1 on another


8. RSTP uses which standard?
802.1w
Flash override (class 4)
On (all ports channel) - auto (channels when asked) - and desirable(actively asks to form a channel)
Connects to a router - firewall - or gateway. Can communicate with anything else connected to the primary or any secondary. Ignores pvlan config


9. What are the RSTP port roles?
Hosts associated with a secondary VLAN can communicate with ports on the primary but not with another secondary VLAN
Hold time is 3xhello. A skew time of 256ms-routerpriority)/256ms is added
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.
Root - designated - alternate - and backup


10. What types of links can be trunked?
Yes
1500B
The campus network's backbone
FE - GE - and aggregated FE/GE Etherchannels


11. What is the portr ID?
1-65535 (def 32768) lower priority - higher probability
16 bits (8b port priority - 8b port number)
If the switch or the powered device doesn't suport power class discovery
Src-ip - dst-ip - src-dst-ip - src-mac - dst-mac - src-dst-mac - src-port - dst-port - src-dst-port


12. What does the standby HSRP router do?
Gateway load balancing protocol - cisco proprietary
Only the standby monitors the hello messages from the active router
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
The time interval that a switch stores a DBPU before discarding it. Default 20 seconds


13. How does 802.3af do power discovery?
Sends a voltage across the receive pairs to detect a 25k ohm resistance
The port is forced to always authorize any connected client with no authentication necessary (default)
Receives the first packet of a traffic flow and routes it
The DCF interframe space- the random backoff time before a wireless set can transmit


14. What pins does FE use?
2 seconds (def)
1/2 and 3/6
Every switch and router in a network must be configured with appropriate QoS features and policies
On all switches in network to enable RLQ request and reply


15. What are the gotchas for uplinkfast?

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


16. can root guard and bdpu guard be used together?
5 classes with 3 drop precedences
Yes
Cisco ILP and 802.3af
No


17. What are the 2 power over ethernet methods?
Two distribution switches that aggregate one or more access switches
Cisco ILP and 802.3af
Must be same type - speed - VLAN(s) - native vlan - pass the same set of vlans -duplex - and spanning tree settings
Distribution layer


18. What data does DHCP snooping track?
Completed dhcp bindings - mac addresses - IP addresses - etc.
No because they only participate if asked
Distributed coordinion function - the use of timers to prevent wireless collisions
A point to point port type but the neighboring device runs traditional 802.1D STP


19. What is a root link query (RLQ)?
Backbonefast uses RLQ to determine if upstream switches have stable connections to root bridge
A single broadcast domain
Used to switch packets destined for the null interface
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.


20. What are the 3 ways GLBP load-balances?
Round robin - weighted - or host-dependent
When a wireless station transmits a frame - the receiving one must send an ack
Traffic types and patterns - amount of L3 switching cap. At dist. Layer - # users at access layer - geography - size of spanning tree domains
By an ARP access list that defines the permitted bindings


21. What is the format of the VRRP virtual MAC?
0000.5e00.01xx
802.11
134 bits
1- inferior BDPU on blocked-considered alternative - 2-inferior on root-all blocked ports considered alternate - 3-if inferior arrives on root and no blocked ports - assumes loss of connectivity to root


22. Can ARP replies be checked
Yes
First configure a L3 interface in same VLAN as clients - then use the ip helper-address command to ID the DHCP server
By configuring every switch port to have an expected and controlled behavior
When each AP stands alone within the larger network.


23. How do you enable CEF?
Half because transmitting and receiving stations use the same frequency
Sends special layer 2 UDLD frames and expects an echo. Both ends must be configured for UDLD
It is enabled by default on all CEF capable switches
The port is forced to always authorize any connected client with no authentication necessary (default)


24. What is integrated services model QOS?
Auto mode
A path is pre-arranged for priority along the complete path from source to destination using the RSVP protocol.
Half-duplex
Real-time Transport Protocol


25. What is a PVLAN?
Best effort delivery - integrated services model - and differentiated services model
Each frame transmits its expected duration time
A private VLAN can be logically associated with a special secondary vlan
Distribution


26. How does HSRP port tracking work?

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


27. can root guard and loop guard be used together
Group (0-255) - priority (1-254 254 is highest - 100 default)
Arp for local subnet - if on different subnet - will arp for dgw
The frame tag contains a 3 but portion tagged from 0 (low) to 7 (high)
No


28. What is a CEF punt?

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


29. How often are HSRP hellos sent?
By name - config revision - and instance to vlan mapping table
Disabled - init - listen - speak - standby - active
L2
3 seconds. Holdtime =3 hellos + 1


30. RSTP root port
Port with best root path cost
Distributed coordinion function - the use of timers to prevent wireless collisions
Using a mobility exchange message
1- inferior BDPU on blocked-considered alternative - 2-inferior on root-all blocked ports considered alternate - 3-if inferior arrives on root and no blocked ports - assumes loss of connectivity to root


31. What can cause a wireless client to switch between Aps?
Used when there are 1 or more VLANs mapped to a single STP instance
Untrusted
The TOS field in the header is used. 2 methods 3 bits or 6 bits
Missed beacons - dropped packets (max retry) - weak signal (data rate switches down) - an AP periodicallytries to find a stronger signal


32. What is the distribution layer best practice?
Isolated and community
Sends a voltage across the receive pairs to detect a 25k ohm resistance
The distribution layer should have only L3 links
Causes switch to actively determine whether alternative paths exist to root bridge in case ther eis an indirect failure


33. How does DAI work?
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
Trunk
No
All ARP packets that arrive on untrusted ports are inspected.


34. What is an untrusted port under dhcp snooping?
Can send and receive BDPUs
Port with redundant - but less deisrable connection to a segment. Possibly root candidate
Any dhcp reply coming from an untrusted port is discarded and the offending port is put in errdisable
134 bits


35. How many MST instances can be in a region?
Use the spanning-tree root macro
16 - IST gets MSTI 0 - 1-15 are available for use. MSTIs are locally significant to the MST region
Both layer 2 switching and IVR
When each AP stands alone within the larger network.


36. How many 802.3af power classes are there?
900 MHz - 2.4Ghz - and 5-6GHz
5 (0-4 with 4 being the highest)
If a proposal is received - the recipient isolates - all nonedge ports blocked until proposal sent causing neighbors to synch - which propagates out in waves
By default weight is 100. Can be made dynamic per interface


37. How do you implement MST?

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


38. What is a LACP priority?
The priority is a 2 byte value followed by the MAC that decides which ports are actively participating in Etherchannel (lower=higher priority)
1-name the chain - 2-establish a key number - 3-create the key string - 4-apply the chain to the string
2 seconds (def)
MAC of the end device


39. What categories can ports be in with dhcp snooping enabled?
Gateway load balancing protocol - cisco proprietary
Trusted or untrusted
Edge - root - and point to point
When the size of a cell is intentionally reduced


40. What does VTP do?
A client can roam to any WLC as long as it stays in a mobility group
The frame tag includes a 3 bit COS value from 0 (low) to 7 (high). Native vlans are untagged so no COS
Manages addition - deletion and renaming VLANs across the network
Normal and aggressive


41. What are the 4 steps in DHCP negotiation?
Port is forced to never authorize any connected client
The active router. All other routers are in backup state
1-client sends DHCP discover as broadcast - 2-DHCP server sends DHCP offer - client sends DHCP Request - DHCP server sends DHCP ack
Routers are assigned to common GLBP group. All routers can be active and can load balance


42. What is the default network diameter?
Disabled - init - listen - speak - standby - active
7 switches from root bridge
Sends a test tone on the transmit pair. If a device is detected - CDP is used to narrow down the power class.
802.1x with EAP over LAN (EAPOL)


43. What is a bridge ID made up of?
Switching Database Manager - configures and prunes TCAM partitions
Almost eliminates listening and learning states for single hosts on an access link
Bridge priority and MAC
Switch(config-if)# standby xx where x= group number


44. What does the RP do?
The station can transmit immediately and wait for an ack
Receives the first packet of a traffic flow and routes it
Using a single WAP to centralize access and control over a group of wireless devices.
It can't


45. What is a proxy arp?

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


46. What is the core block?

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


47. What is SSO?

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


48. By default - what layer do catalyst switchports operate on?
Isl - dot1q - negotiate (default)
L2
Etherchannel ports have inconsistent config
Using a mobility exchange message


49. Automatically configure STP timers
Use the spanning-tree root macro
Control functions
Weak key rotation
It's a router that maintains routes (static or dynamic) - and populates the FIB


50. What is unique about HSRP group numbers?
When the size of a cell is intentionally reduced
Dynamic WEP keys that change periodically
Notifies upstream neighbors by sending multicasts on behalf of hosts at the interval of the max update rate parameter.
They are locally significant on an interface. HSRP1 on one VLAN is different from HSRP1 on another