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 happens when the topology changes?

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2. What is a CEF glean?

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3. What are the restrictions for bundling into an Etherchannel?
Must be same type - speed - VLAN(s) - native vlan - pass the same set of vlans -duplex - and spanning tree settings
CEF is distributed completely among multiple L3 forwarding engines.
Switching Database Manager - configures and prunes TCAM partitions
It can't


4. How doed backbonefast work?
Full duplex
Admin down
Src-ip - dst-ip - src-dst-ip - src-mac - dst-mac - src-dst-mac - src-port - dst-port - src-dst-port
By short-circuiting the max age timer


5. How do Cisco IP phones communicate with the CCM?
Nonstop forwarding is an interactive method focusing on rebuilding the RIB after SUP switchover
With the skinny protocol
Because each frame is checked
For hosts that doesn't understand routing - the DGW is configured to reply with its own mac


6. What is RPVST+?
The port is forced to always authorize any connected client with no authentication necessary (default)
An instance of RSTP running for each VLAN on the switch. Changing from PVST to RPVST+ is disruptive
Configure and enable DHCP snooping
Because each frame is checked


7. What is portfast?
Almost eliminates listening and learning states for single hosts on an access link
Based on priority (0-255). Default is 100. Highest IP is tie breaker
0000.0c07.acxx where xx is the group number as a 2-digit hex value
Multicasts to 224.0.0.18 (VRRP)


8. What does UDLD do?
Protects STP when a physical malfunction only allows traffic in 1 direction - even though the link shows as up (cisco proprietary)
Switchpotrt nonegotiate
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


9. How is UDLD configured?
MST attributes must be manually entereed on each switch in the region. They don' t propagate like VTP.
2 seconds
Per-port or globally for all fiber-optic ports. Can be enabled globally - but will only affect fiber ports
Both layer 2 switching and IVR


10. 802.11g
VTP server for domain null with no password or secure mode
A single broadcast domain
Yes
Compatible with 802.11b - up to 54Mbps in 12 data rates - 3 channels - 2.4Ghz


11. What is the traditional MLS view of switching?
Route once - switch many
The station must wait until the frame in progress has completed - then wait a random amount of time before transmitting
All nondesignated ports - but ok for all ports
The priority is a 2 byte value followed by the MAC that decides which ports are actively participating in Etherchannel (lower=higher priority)


12. How do you prevent switch spoofing?
Either desirable or auto mode
26-byte header - 4-byte trailer with CRC
By configuring every switch port to have an expected and controlled behavior
No


13. What can cause a wireless client to switch between Aps?
Data goes over native vlan - voice goes over VLAN0 - voice QOS is 802.1p
A host port goes up or down
The switch checks the MAC and IP reported in the reply against trusted values. If they don't match - it is dropped and logged
Missed beacons - dropped packets (max retry) - weak signal (data rate switches down) - an AP periodicallytries to find a stronger signal


14. Of what significance are private VLANs
Local only
From the DHCP snooping database or from static entries
Critical...used most often for IPT
RPR - RPR+ - and SSO


15. At what layer does EAPOL run?
Configure the timer on the AVG and let it propagate
Causes switch to actively determine whether alternative paths exist to root bridge in case ther eis an indirect failure
L2
Enables portfast - sets the port to access and disables PAgP


16. What is the portr ID?
16 bits (8b port priority - 8b port number)
Priority (class 1)
If any BDUP is received on a port - it puts the port into the errdisable state
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


17. What is jitter?
Variation in delay
Edge - root - and point to point
Dynamic arp inspection
Disabled - init - listen - speak - standby - active


18. What is a wireless mobility group?
A client can roam to any WLC as long as it stays in a mobility group
Compatible with 802.11b - up to 54Mbps in 12 data rates - 3 channels - 2.4Ghz
Checks the destination MAC in the header against the target MAC in the ARP reply
They must be carried over a voice VLAN (VVID) or over a regular data VLAN (ie. The native VLAN or the PVID)


19. what should you do if you expect a PAgP capable switch at the other end vs. a server or host?
Configure non-silent submode
When a client roams between Aps in different subnets
No
Distributed coordinion function - the use of timers to prevent wireless collisions


20. Where is bdpu guard enabled?
Edge - root - and point to point
Using a mobility exchange message
On ports where you never expect to find a root bridge for a VLAN
All user ports that have portfast enabled


21. How does RSTP identify a topology change?
Global config (vlan - vtp mode - and vtp domain) and VLAN DB mode commands. Global config is preferred because VLAN DB mode commands are legacy
Only when a nonedge port transitions to forwarding
An L2 switch can only forward frames best effort unless going across a trunk
The port is forced to always authorize any connected client with no authentication necessary (default)


22. What are the 3 RSTP port types?
L2
Edge - root - and point to point
Isolated and community
Discarding - learning - forwarding


23. What does the ip option do when checking ARP replies

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24. What is the size of a TCAM value?
When the AP uplinks to an Ethernet network.
134 bits - consisting of source and destination addresses and protocol information from the packet or frame
Data and voice over native vlan no QOS and no 802.1p trunk
Per VLAN


25. What is the port number range?
0-255
Only on ports that have same static VLANs or trunking. It also modifies parameters of the channel if one of the ports is modified
Port
1 -2 -5.5 and 11 Mbps - Channels 1/6/11 - 2.4Ghz


26. What are the steps to configuring HSRP MD5 authentication?
Configuration and TCN
Effectively stops STP on filtered ports
1-name the chain - 2-establish a key number - 3-create the key string - 4-apply the chain to the string
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


27. What types of authentication does HSRP allow?
Only on ports that have same static VLANs or trunking. It also modifies parameters of the channel if one of the ports is modified
Plain text or md5
Sends special layer 2 UDLD frames and expects an echo. Both ends must be configured for UDLD
The distribution layer should have only L3 links


28. Which fiber is the receive?
On the left as you face the connector
Plain text or md5
A router keeps a routing table and an ARP table. The FIB combines them for every next-hop entry
Usually QoS from VOIP but not PC dataa


29. What contains the next-hop entries?
The switch checks the MAC and IP reported in the reply against trusted values. If they don't match - it is dropped and logged
Manages addition - deletion and renaming VLANs across the network
First configure a L3 interface in same VLAN as clients - then use the ip helper-address command to ID the DHCP server
FIB


30. What are the VRRP group and priority numbers?
Compatible with 802.11b - up to 54Mbps in 12 data rates - 3 channels - 2.4Ghz
The standby becomes active and stays active by default. Preemption can be configured
Group (0-255) - priority (1-254 254 is highest - 100 default)
When a specific interface is tracked - HSRP reduces it's priority after a specified interval.


31. How does the CEF L3 engine operate?

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32. Does GLBP allow preemption?
All ports where root isn't expected
Yes
A packet can't be switched in hardware with the FIB and must go to the L3 engine
A point to point port type


33. How is the IPT 802.1 trunk negotiated?
Port is forced to never authorize any connected client
Distribution layer
Automatically using DTP and CDP
The active router. All other routers are in backup state


34. How often are HSRP hellos sent?
1/2 and 3/6
If three are missed in a row - the neighbor is considered down and the data for that neighbor is aged
3 seconds. Holdtime =3 hellos + 1
Disabled - blocking - listening - learning - forwarding


35. What is the SDM?
Switching Database Manager - configures and prunes TCAM partitions
1- trunking mode - 2-trunk encapsulation - 3-native VLAN - 4-allowed VLAN
LWAPP (Cisco proprietary) and CAP-WAP (standards based)
1-client sends DHCP discover as broadcast - 2-DHCP server sends DHCP offer - client sends DHCP Request - DHCP server sends DHCP ack


36. What are the two private vlan association modes?
Matching SSID - compatible data rate - authentication credentials
Untrusted
Promiscuous and host
Disabled - init - listen - speak - standby - active


37. What is route caching?

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38. What are the 3 trunk encap modes?
Isl - dot1q - negotiate (default)
Group (0-1023) priority (1-255 higher better def 100)
Receives the first packet of a traffic flow and routes it
2-8 FE - GE - or 10GE are bundled.


39. How does HSRP election work?
Based on priority (0-255). Default is 100. Highest IP is tie breaker
Limits the number if dhcp requests on a port
Disabled - init - listen - speak - standby - active
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


40. What is DAI?
They must be carried over a voice VLAN (VVID) or over a regular data VLAN (ie. The native VLAN or the PVID)
Half-duplex
A point to point port type but the neighboring device runs traditional 802.1D STP
Dynamic arp inspection


41. What is an IBSS?
Incoming frames dropped - but MACs learned
Embeds the tag within the frame
The wireless clients communicate directly with no other means of connectivity such as a WAP
To the virtual port-channel interface


42. What address does HSRP send hello packets to?
When the AP uplinks to an Ethernet network.
FIB
Matching SSID - compatible data rate - authentication credentials
224.0.0.2 (all routers)


43. How do you show HSRP status
Hosts within a secondary can communicate with each other and with the primary - but not with another secondary vlan
On ports where you never expect to find a root bridge for a VLAN
Show standby
Allows devices to interoperate with PVST and CST. Can use both dot1q and ISL


44. unknown unicast flooding
The active router. All other routers are in backup state
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.
Reboots and searches for a new WLC
Configure the timer on the AVG and let it propagate


45. What data does DHCP snooping track?
Reboots and searches for a new WLC
Completed dhcp bindings - mac addresses - IP addresses - etc.
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
Differentiated services


46. What are the RSTP port states?
Lowest cumulative cost to root
0-255
Discarding - learning - forwarding
FE and GE


47. What does the version number indicate when looking at CEF entries?
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
Show standby
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 number of times the entry has been updated since the table was generated


48. If a wireless station needs to transmit and no other device is transmitting - what happens?
The station can transmit immediately and wait for an ack
Source IP - dest IP - combination of source and dest IP - source and dest MAC - or TCP/UDP port numbers
Src-ip - dst-ip - src-dst-ip - src-mac - dst-mac - src-dst-mac - src-port - dst-port - src-dst-port
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


49. How do VRRP routers handle preemption?
On by default
Round robin - weighted - or host-dependent
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
Gets assistance from other NSF-aware neighbors. NSF features need to be built into the routing protocols on router needing and providing assistance


50. What if RSTP BDPUs aren't received?
Disabled - init - listen - speak - standby - active
Makes use of the DHCP snooping database and static ip source binding entries. If enabled - switch will test addresses
If three are missed in a row - the neighbor is considered down and the data for that neighbor is aged
The redundant SUP is booted and sup and route engine is init'd. No L2 or L3 functions are started. Allows switchports to retain state