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 the rewrite engine do?
Port that connects to another switch and becomes a designated port
It updates the L2 headers with the proper src and dst MAC - L3 TTL - L3 checksum - and L2 checksum information
5 (0-4 with 4 being the highest)
Use sh interface on the interface and look for error counts > 10


2. Where does VRRP send advertisements?
Automatically by duplex mode in use. Full duplex are point ot point. Half duplex ports use traditional 802.1D convergence is used.
Multicasts to 224.0.0.18 (VRRP)
Show standby
Used when there are 1 or more VLANs mapped to a single STP instance


3. How does the standby handle ARP issues after it becomes active?
By sending a gratuitous ARP
7 switches from root bridge
Create 2 hsrp groups - each with the active router being different switches - then have clients point to each
Sets the switchport mode to access - enables portfast - and turns off channel grouping for the port


4. What are the 3 trunk switchport modes?
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
Route once - switch many
The port uses 802.1x exchange to move from unauthorized to authorized. Requires app on client
Trunk - dynamic auto - dynamic desireable (default)


5. When looking at the sh spanning tree output - What does P2P peer(STP) denote?
1-name the chain - 2-establish a key number - 3-create the key string - 4-apply the chain to the string
Effectively stops STP on filtered ports
1-(opt) configure load balancing - 2-select the interface(s) - 3-assign the protocol - 4-select the mode and submode
A point to point port type but the neighboring device runs traditional 802.1D STP


6. How is an RSTP edge port configured
If a proposal is received - the recipient isolates - all nonedge ports blocked until proposal sent causing neighbors to synch - which propagates out in waves
Configure non-silent submode
With portfast
No


7. What is the DIFS?
The DCF interframe space- the random backoff time before a wireless set can transmit
Turn on port security
Between interfaces that are assigned to L2 VLANs or L2 trunks
By using a trunk link


8. What is the port number range?
They shorten their bridge table aging times from default (300sec) to the fowarding delay (15 sec)
0-255
By encapsulating each frame in a header and trailer
Using a mobility exchange message


9. What does MSTP consist of?
Critical...used most often for IPT
Single instance of STP for all VLANs. BDPUs are sent over trunks using the native VLAN with untagged frames. Dot1q based
1 IP subnet
Regions and instances


10. How do you renable an err-disable port by default?
An AP's coverage area
Two distribution switches that aggregate one or more access switches
4
Manually


11. What is DAI?
Roughly 50%
Dynamic arp inspection
Distribution layer
An L2 switch can only forward frames best effort unless going across a trunk


12. What is a wireless mobility group?
Low cost - high density ports - multiple scalable uplinks - vlans - traffic and protocol filtering and QoS
A client can roam to any WLC as long as it stays in a mobility group
By short-circuiting the max age timer
Only for the offending VLAN on the port


13. What are the three basic types of QOS?
The frame tag contains a 3 but portion tagged from 0 (low) to 7 (high)
LACP port priority
Best effort delivery - integrated services model - and differentiated services model
1-1005 (1 and 1002-1005 are reserved)


14. What is the SDM?
They are locally significant on an interface. HSRP1 on one VLAN is different from HSRP1 on another
Controls where candidate root bridges can be connected and found on a network
Switching Database Manager - configures and prunes TCAM partitions
5 classes with 3 drop precedences


15. What is the VRRP skew time?
1-lowest root bridge ID - 2-lowest root path cost - 3-lowest bridgeID - 4-lowest port ID
Hold time is 3xhello. A skew time of 256ms-routerpriority)/256ms is added
Must be same type - speed - VLAN(s) - native vlan - pass the same set of vlans -duplex - and spanning tree settings
When each AP stands alone within the larger network.


16. By default - what submode does PAgP operate in with the desirable and auto modes?
Routers at the distribution layer become the bottlenecks or broadcast or multicast traffic slows the switches in the switch block
Silent
Switch(config-if)# standby xx where x= group number
A VLAN that spans the entire fabric


17. How many virtual MACs can GLBP have?
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
Only on ports that have same static VLANs or trunking. It also modifies parameters of the channel if one of the ports is modified
7 switches from root bridge
Up to 4 can be used in a group. Called active virtual forwarders (AVF)


18. How can you load-balance with HSRP?
By default weight is 100. Can be made dynamic per interface
Create 2 hsrp groups - each with the active router being different switches - then have clients point to each
Root
802.1x with EAP over LAN (EAPOL)


19. How does a Cisco IP phone connect upstream?
A host port goes up or down
A client can roam to any WLC as long as it stays in a mobility group
Via an 802.1Q trunk or a single VLAN access port
The number of STP instances needed ot support the desired topologies and whether to map a set of VLANs to each instance


20. What are the PAgP negotiation modes
On (all ports channel) - auto (channels when asked) - and desirable(actively asks to form a channel)
Using a mobility exchange message
The priority is a 2 byte value followed by the MAC that decides which ports are actively participating in Etherchannel (lower=higher priority)
PAgP (Cisco proprietary) and LACP (standards-based)


21. What is a topology change?
If any BDUP is received on a port - it puts the port into the errdisable state
When a port moves into forwarding or from fowarding or learning to blocking.
The point at which a switch decides to trust incoming Qos. Usually at boundary with ISP
Using a single WAP to centralize access and control over a group of wireless devices.


22. What is the STP learning state?
Critical...used most often for IPT
The RP listens to a flow's 1st packet for the dest. The SE listens to the packet and dest and puts a shortcut in the MSL cache. Netflow switching - route once - switch many
After forwarding delay - port can learn new MAC addresses
Turn on port security


23. What happens during HSRP failover?
The standby becomes active and stays active by default. Preemption can be configured
Hashing algorithm
The wireless clients communicate directly with no other means of connectivity such as a WAP
MAC of the end device


24. Where are security and QoS ACLs stored?
Distribution layer
Automatically by duplex mode in use. Full duplex are point ot point. Half duplex ports use traditional 802.1D convergence is used.
TCAM
900 MHz - 2.4Ghz - and 5-6GHz


25. What is a drop adjacency?

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


26. How can BDPU Guard be configured?
Roughly 2000
Data and voice over native vlan - no QOS but still uses 802.1p trunk
Checks the source MAC in the header against the sender MAC in the ARP reply
Globally or per-port


27. How does 802.3af do power discovery?
It updates the L2 headers with the proper src and dst MAC - L3 TTL - L3 checksum - and L2 checksum information
Sends a voltage across the receive pairs to detect a 25k ohm resistance
On ports where you never expect to find a root bridge for a VLAN
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.


28. What is a null adjacency?
Used to switch packets destined for the null interface
Isl - dot1q - negotiate (default)
LACP port priority
All user ports that have portfast enabled


29. How does loop guard block ports?
Etherchannel ports have inconsistent config
Only for the offending VLAN on the port
Use the spanning-tree root macro
Arp for local subnet - if on different subnet - will arp for dgw


30. Where is root guard enabled?

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


31. What do you need to determine to use MSTP?
To a VLAN and not to a VLAN interface (SVI)
Critical...used most often for IPT
The number of STP instances needed ot support the desired topologies and whether to map a set of VLANs to each instance
Source IP - dest IP - combination of source and dest IP - source and dest MAC - or TCP/UDP port numbers


32. Define VRRP
Virtual Router Redundancy Protocol - pretty much the same as HSRP
Up to 4 can be used in a group. Called active virtual forwarders (AVF)
Once the CCM gives them the parameters - they use RTP
Checks the destination MAC in the header against the target MAC in the ARP reply


33. What is a cell?

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


34. How does HSRP port tracking work?

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


35. RSTP edge port
Plain text or md5
Dynamic WEP keys that change periodically
Only a single host connects . If one BDPU is received - it is no longer an edge port
All nondesignated ports - but ok for all ports


36. How often are VRRP advertisements sent?
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
1- trunking mode - 2-trunk encapsulation - 3-native VLAN - 4-allowed VLAN
1 second. Backup routers can learn the interval from the master
A router keeps a routing table and an ARP table. The FIB combines them for every next-hop entry


37. What is the cost of a 100Mbps link?
The priority is a 2 byte value followed by the MAC that decides which ports are actively participating in Etherchannel (lower=higher priority)
19
Source IP and MAC must match those addresses learned by DHCP snooping or a static entry
Port stays up - packets from violating MACs dropped - no logging


38. What is the default 10mbps Enet duplex?
Half-duplex
No shut
Makes use of the DHCP snooping database and static ip source binding entries. If enabled - switch will test addresses
The total delay from start to finish


39. How does VRRP do tracking?

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


40. How do you prevent switch spoofing?
L2
No
1/2 and 3/6
By configuring every switch port to have an expected and controlled behavior


41. What is a discard adjacency?
Packets are discarded due to an ACL or policy action
CEF is distributed completely among multiple L3 forwarding engines.
The number of STP instances needed ot support the desired topologies and whether to map a set of VLANs to each instance
Between any type of interface as long as the interface can have an L3 address assigned


42. 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-(opt) configure load balancing - 2-select the interface(s) - 3-assign the protocol - 4-select the mode and submode
Port stays up - packets from violating MACs dropped - no logging
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.


43. What are the 5 STP port roles?
Weak key rotation
Receives the first packet of a traffic flow and routes it
Discarding - learning - forwarding
Root - designated - blocking - alternate - forwarding (host)


44. Which 4 things must be agreeable to trunk?
For hosts that doesn't understand routing - the DGW is configured to reply with its own mac
Up to 4 can be used in a group. Called active virtual forwarders (AVF)
Sets the switchport mode to access - enables portfast - and turns off channel grouping for the port
1- trunking mode - 2-trunk encapsulation - 3-native VLAN - 4-allowed VLAN


45. What is the default FE duplex?
Full duplex
Global config (vlan - vtp mode - and vtp domain) and VLAN DB mode commands. Global config is preferred because VLAN DB mode commands are legacy
By using an Ether-IP tunnel
They disguise the origin of an attack


46. can root guard and udld be used together?
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
With portfast
Yes
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


47. What is UDLD normal mode?
Lowest cumulative cost to root
If a unidirectional link is detected - the port continues normally - but the port is marked as undetermined and a syslog is generated
1 -2 -5.5 and 11 Mbps - Channels 1/6/11 - 2.4Ghz
The port uses 802.1x exchange to move from unauthorized to authorized. Requires app on client


48. What types of ports autonegotiate?
Each physical interface has a different IP address. All physical interfaces point to a virtual interface called the standby address or VIP
Turn on port security
FE and GE
Each frame transmits its expected duration time


49. How is RSTP synchronization accomplished?
The frame tag includes a 3 bit COS value from 0 (low) to 7 (high). Native vlans are untagged so no COS
Limits the number if dhcp requests on a port
10-15%
All non-edge ports are discarding. After the root bridge is identified - the port with superior BDPU becomes root


50. What are the steps to configure MST?
Half because transmitting and receiving stations use the same frequency
Reboots and searches for a new WLC
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
A key string of up to 8 characters is sent. Default is cisco.