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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 does port-security restrict do?
The time interval that a switch stores a DBPU before discarding it. Default 20 seconds
Port stays up - but packets from violating MACs are dropped. Switch logs violating packets
L2
Time between BDPUs sent by root bridge. Default of 2 seconds

2. How does HSRP do MD5 authentication?
Can send and receive BDPUs
By using a hash of a key string
Automatically using DTP and CDP
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

3. Can MSTP interoperate with 802.1q and/or PVST+?
The TOS field in the header is used. 2 methods 3 bits or 6 bits
Limits the number if dhcp requests on a port
The time that a port spends in both listening and learning states . Default 15 seconds
Yes to both

4. What can the Etherchannel hash use?
Host Standby Router protocol. Cisco proprietary. Switch is either active - standby - or listen
63 kbps
Source IP - dest IP - combination of source and dest IP - source and dest MAC - or TCP/UDP port numbers
Disabled - blocking - listening - learning - forwarding

5. What 2 tunnelling mechanisms do the LAP and WLC use to communicate?
The port uses 802.1x exchange to move from unauthorized to authorized. Requires app on client
LWAPP (Cisco proprietary) and CAP-WAP (standards based)
When a client roams between Aps in different subnets
Checks the destination MAC in the header against the target MAC in the ARP reply

6. How does HSRP election work?
Based on priority (0-255). Default is 100. Highest IP is tie breaker
CEF is distributed across multiple L3 forwarding engines - typically on Catalyst 6500 line cards each having only a subset
Edge - root - and point to point
802.1x with EAP over LAN (EAPOL)

7. What is an IBSS?
Show standby
Cisco recommends only on the root bridge
Only the standby monitors the hello messages from the active router
The wireless clients communicate directly with no other means of connectivity such as a WAP

8. What is the standard for WLANs?
Auto mode
By using a hash of a key string
802.11
The same as a standby group in HSRP

9. What is the GLBP AVG?
4
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
If three are missed in a row - the neighbor is considered down and the data for that neighbor is aged
Per VLAN

10. What is DSCP?
16 bits (8b port priority - 8b port number)
Root
Differentiated services code point
Multicast to 01-80-c2-00-00-00

11. What is the default VTP state?
VTP server for domain null with no password or secure mode
An ac adaptor that plugs into a wall outlet.
Sends a voltage across the receive pairs to detect a 25k ohm resistance
Packets must be sent to the L3 engine for further processing

12. How is 802.1x configured for port security?
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
RADIUS
2-8 FE - GE - or 10GE are bundled.
Either desirable or auto mode

13. What is a root link query (RLQ)?
All fiber-optic links between switches (must be enabled on both ends)
If a unidirectional link is detected - the port continues normally - but the port is marked as undetermined and a syslog is generated
No
Backbonefast uses RLQ to determine if upstream switches have stable connections to root bridge

14. Define VRRP
FE and GE
Isl - dot1q - negotiate (default)
On all switches in network to enable RLQ request and reply
Virtual Router Redundancy Protocol - pretty much the same as HSRP

15. What is an insignificant topology change?
By short-circuiting the max age timer
Configuration and TCN
A host port goes up or down
Checks the destination MAC in the header against the target MAC in the ARP reply

16. How do Cisco IP phones communicate with the CCM?
Hold time is 3xhello. A skew time of 256ms-routerpriority)/256ms is added
L2
Multicasts to 224.0.0.18 (VRRP)
With the skinny protocol

17. Each switch port is a _____ ______
Trusted or untrusted
Collision domain
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
Makes use of the DHCP snooping database and static ip source binding entries. If enabled - switch will test addresses

18. How should the switch port to which a LAP be configured?
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
On ports where you never expect to find a root bridge for a VLAN
Connects to a host on an isolated or community vlan. Communicates only with promiscuous port or ports on same community vlan
Access

19. How can you tell if a switch block is too large?
One that can be detected on a switch interface (ie. Up/down)
Port stays up - but packets from violating MACs are dropped. Switch logs violating packets
Disabled - blocking - listening - learning - forwarding
Routers at the distribution layer become the bottlenecks or broadcast or multicast traffic slows the switches in the switch block

20. What are the caveats for HSRP port tracking?
Another router must have a higher HSRP priority and have preemt set up
L2
Source IP - dest IP - combination of source and dest IP - source and dest MAC - or TCP/UDP port numbers
Show standby

21. How do you disable DTP when you configure both ends of the ISL manually?
Port stays up - packets from violating MACs dropped - no logging
Effectively stops STP on filtered ports
Data goes over native vlan - voice goes over VLAN0 - voice QOS is 802.1p
Switchpotrt nonegotiate

22. 802.11g
The total delay from start to finish
1-(opt) configure load balancing - 2-select the interface(s) - 3-assign the protocol - 4-select the mode and submode
Compatible with 802.11b - up to 54Mbps in 12 data rates - 3 channels - 2.4Ghz
Round robin - weighted - or host-dependent

23. How does RSTP identify a topology change?
Can hear only BDPUs
Another router must have a higher HSRP priority and have preemt set up
Only when a nonedge port transitions to forwarding
2-8 FE - GE - or 10GE are bundled.

24. 802.11b
No
1 -2 -5.5 and 11 Mbps - Channels 1/6/11 - 2.4Ghz
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
19

25. How does GLBP work?
Used to switch packets that can't be forwarded normallly due to an encapsulation failure - unresolved address - unsupported protocol - etc.
Routers are assigned to common GLBP group. All routers can be active and can load balance
1-65535 (def 32768) lower priority - higher probability
CEF is distributed across multiple L3 forwarding engines - typically on Catalyst 6500 line cards each having only a subset

26. What does the static keyword do when applying an arp ACL?
Almost eliminates listening and learning states for single hosts on an access link
Prevents the dhcp binding DB from being checked.
The frame tag contains a 3 but portion tagged from 0 (low) to 7 (high)
Only the standby monitors the hello messages from the active router

27. What must be supported for port-based security to occur?
802.1x with EAP over LAN (EAPOL)
63 kbps
The priority is a 2 byte value followed by the MAC that decides which ports are actively participating in Etherchannel (lower=higher priority)
Causes switch to actively determine whether alternative paths exist to root bridge in case ther eis an indirect failure

28. What is the VRRP master router?
RPR - RPR+ - and SSO
The active router. All other routers are in backup state
Must be same type - speed - VLAN(s) - native vlan - pass the same set of vlans -duplex - and spanning tree settings
Flash override (class 4)

29. How does IPT behave when the voice VLAN is in vlan-id mode?
Distribution layer
Data goes over native vlan - voice goes over specified VLAN - voice QOS is 802.1p
26-byte header - 4-byte trailer with CRC
All L2 connectivity should be contained within the access layer.

30. What is 802.1x force-authorized?
CEF is distributed across multiple L3 forwarding engines - typically on Catalyst 6500 line cards each having only a subset
Switch(config-if)# vrrp xx where xx= group number
Only when a nonedge port transitions to forwarding
The port is forced to always authorize any connected client with no authentication necessary (default)

31. What are the steps of RSTP convergence?
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
Switch(config-if)# vrrp xx where xx= group number
Change in trunk encap
Interim solution - uses same hardware as WEP - but uses TKIP encryption

32. What is the range of PAgP channel group numbers?
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
Cisco recommends only on the root bridge
1 to 64
Used when ACLs specify port ranges...used by TCAM

33. When looking at the sh spanning tree output - What does P2P denote?
Flash (class 3)
Yes
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
A point to point port type

34. What are the PAgP negotiation modes
Virtual Router Redundancy Protocol - pretty much the same as HSRP
It's a router that maintains routes (static or dynamic) - and populates the FIB
Frames that barely exceed 1518B or 1622B due to headers
On (all ports channel) - auto (channels when asked) - and desirable(actively asks to form a channel)

35. What are the 2 types of BDPU?
By sending a gratuitous ARP
Configuration and TCN
If the switch or the powered device doesn't suport power class discovery
Automatically by duplex mode in use. Full duplex are point ot point. Half duplex ports use traditional 802.1D convergence is used.

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

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37. What is the default network diameter?
7 switches from root bridge
Roughly 2000
If the switch or the powered device doesn't suport power class discovery
The ASIC

38. What is the portr ID?
RADIUS
16 bits (8b port priority - 8b port number)
VTP server for domain null with no password or secure mode
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

39. How are multiple VLANs mapped to multiple SSIDs?
Tracks of BDPUs on nondesignated ports. When those BDPUs stop coming - the port is put into loop-inconsistent state and blocks
By using a trunk link
Aggregation - high L3 throughput - security and policy based connectivity functions through access lists and packet filters - QoS - scalable high-speed links
No

40. 802.11a
Isolated and community
Root - designated - blocking - alternate - forwarding (host)
Up to 54Mbps - not cross-compatible - 12 to 23 clean channels - 5.8 Ghz
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

41. How should backbonefast be configured?
Each physical interface has a different IP address. All physical interfaces point to a virtual interface called the standby address or VIP
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
On all switches in network to enable RLQ request and reply
Used when ACLs specify port ranges...used by TCAM

42. How does every GLBP command begin
63 kbps
Switch(config-if)# glbp xx where xx = group number
Untrusted
Switchpotrt nonegotiate

43. What is the port priority range?
Aggregation - high L3 throughput - security and policy based connectivity functions through access lists and packet filters - QoS - scalable high-speed links
0-255 (lower is better)
Controls where candidate root bridges can be connected and found on a network
Route once - switch many

44. What does DTP do?
Connects to a router - firewall - or gateway. Can communicate with anything else connected to the primary or any secondary. Ignores pvlan config
After another forwarding delay - the port can send and receive data frames - collect MAC addresses - and send and receove BDPUs
Automatically negotiates a common trunk mode between switches
Multicast to 01-80-c2-00-00-00

45. What is the STP forward delay timer?
The time that a port spends in both listening and learning states . Default 15 seconds
The port asks the other end to trunk
Almost eliminates listening and learning states for single hosts on an access link
Virtual Router Redundancy Protocol - pretty much the same as HSRP

46. Can ARP replies be checked
Yes
Each frame transmits its expected duration time
1-65535 (def 32768) lower priority - higher probability
300 sec by default

47. What is errdisable dtp-flap?
Reboots and searches for a new WLC
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
Change in trunk encap
Very high L3 throughput - no access lists or port filtering - redundancy and resilience - advanced QoS

48. What happens when switches receive a configuration BDPU?
They shorten their bridge table aging times from default (300sec) to the fowarding delay (15 sec)
Packets are discarded due to an ACL or policy action
By encapsulating each frame in a header and trailer
Group (0-1023) priority (1-255 higher better def 100)

49. What is an IST instance?
To a VLAN and not to a VLAN interface (SVI)
Within a single MST region - an IST instances runs to work out a loop free topology between links where CST meets the region boundary and all switches in the region. It runs at the boundary.
Bridge priority and MAC
A host port goes up or down

50. Where is UDLD enabled?
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
Hosts associated with a secondary VLAN can communicate with ports on the primary but not with another secondary VLAN
All fiber-optic links between switches (must be enabled on both ends)
By configuring every switch port to have an expected and controlled behavior