Free pass4sure ccie 350-001 v2.93 Download

CCIE-ROUTING AND SWITCHING QUALIFICATION (Written exam) : 350-001 Exam

Exam Number/Code: 350-001
Exam Name: CCIE-ROUTING AND SWITCHING QUALIFICATION (Written exam)
VUE Code: 350-001
Questions Type: Single choice,
Real Exam Question Numbers: 100 questions
Exam Language(s): English

“CCIE-ROUTING AND SWITCHING QUALIFICATION (Written exam)”, also known as 350-001 exam, is a Cisco certification.
Preparing for the 350-001 exam Searching 350-001 Test Questions, 350-001 Exam, 350-001 Dumps

With the complete collection of questions and answers Q&as with Expert Explanations, Pass4sure has assembled to take you through 408 Q&As to your 350-001 Exam preparation. In the 350-001 exam resources, you will cover every field and category in CCIE helping to ready you for your successful Cisco Certification. The written exam is a two-hour, multiple choice test with 100 questions covering Routing and Switching networking theory related to topics such as IP, IP routing, non-IP desktop protocols, bridging and switch-related technologies, and includes some equipment commands. The exam is closed book and no outside reference materials are allowed.

QUESTION 51
Troubleshooting STP convergence errors within the PassGuide LAN reveals that it
has multiple bridging loops. What Cisco IOS switching feature, when improperly
implemented, is most likely the cause of these errors?
A. Port Fast
B. Uplink Fast
C. Backbone Fast
D. Dot1q Trunking
E. Fast EtherChannel
F. None of the above
Answer: A
Explanation:
Spanning tree PortFast causes a spanning tree port to enter the forwarding state
immediately, bypassing the listening and learning states. You can use PortFast on switch
350-001
www.actualtest.org – The Power of Knowing
ports connected to a single workstation or server to allow those devices to connect to the
network immediately, rather than waiting for spanning tree to converge. PortFast should
be used only when connecting a single end station to a switch port. Otherwise, you might
create a network loop.
Incorrect Answers:
B. UplinkFast provides fast convergence after a spanning tree topology change and
achieves load balancing between redundant links using uplink groups. An uplink group is
a set of ports (per VLAN), only one of which is forwarding at any given time.
Specifically, an uplink group consists of the root port (which is forwarding) and a set of
blocked ports, except for self-looping ports. The uplink group provides an alternate path
in case the currently forwarding link fails.
C. BackboneFast is initiated when a root port or blocked port on a switch receives
inferior BPDUs from its designated bridge. An inferior BPDU identifies one switch as
both the root bridge and the designated bridge. When a switch receives an inferior
BPDU, it indicates that a link to which the switch is not directly connected (an indirect
link) has failed (that is, the designated bridge has lost its connection to the root bridge).
Under normal spanning tree rules, the switch ignores inferior BPDUs for the configured
maximum aging time.
The switch tries to determine if it has an alternate path to the root bridge. If the inferior
BPDU arrives on a blocked port, the root port and other blocked ports on the switch
become alternate paths to the root bridge. (Self-looped ports are not considered alternate
paths to the root bridge.) If the inferior BPDU arrives on the root port, all blocked ports
become alternate paths to the root bridge. If the inferior BPDU arrives on the root port
and there are no blocked ports, the switch assumes that it has lost connectivity to the root
bridge, causes the maximum aging time on the root to expire, and becomes the root
switch according to normal spanning tree rules.
If the switch has alternate paths to the root bridge, it uses these alternate paths to transmit
a new kind of PDU called the Root Link Query PDU. The switch sends the Root Link
Query PDU out all alternate paths to the root bridge. If the switch determines that it still
has an alternate path to the root, it causes the maximum aging time on the ports on which
it received the inferior BPDU to expire. If all the alternate paths to the root bridge
indicate that the switch has lost connectivity to the root bridge, the switch causes the
maximum aging times on the ports on which it received an inferior BPDU to expire. If
one or more alternate paths can still connect to the root bridge, the switch makes all ports
on which it received an inferior BPDU its designated ports and moves them out of the
blocking state (if they were in blocking state), through the listening and learning states,
and into the forwarding state.
D. The 802.1Q trunking method is the industry standard for trunk links, and can be used
as an alternative to ISL. The use of either trunking method alone will not cause any
bridging loops.
E. Fast Etherchannel simply provides a way to bond multiple Ethernet links into one
larger channel. It will not introduce any STP loops into the network.
QUESTION 52
Switch CK1 is running the rapid spanning tree protocol (RSTP). Upon a topology
change, what happens to dynamic entries in the L2 forwarding table?
350-001
www.actualtest.org – The Power of Knowing
A. Only entries behind port where TC was received are removed
B. All entries are removed except for those behind edge ports and the port where TC was
received
C. All entries are removed (purged)
D. All entries are removed except for entries behind edge ports
E. Aging timer it set to 15 seconds, so idle entries age out
F. None of the above
Answer: B
Explanation:
Topology Change Detection
In RSTP, only non-edge ports moving to the forwarding state cause a topology change.
This means that a loss of connectivity is not considered as a topology change any more,
contrarily to 802.1d (that is, a port that moves to blocking no longer generates a TC).
When a RSTP bridge detects a topology change, the following happens:
1. It starts the TC While timer with a value equal to twice the hello time for all its
non-edge designated ports and its root port if necessary.
2. It flushes the MAC addresses associated with all these ports.
Topology Change Propagation
When a bridge receives a BPDU with the TC bit set from a neighbor, the following
happens:
1. It clears the MAC addresses learnt on all its ports except the one that received the
topology change.
2. It starts the TC While timer and sends BPDUs with TC set on all its designated ports
and root port (RSTP no longer uses the specific TCN BPDU, unless a legacy bridge
needs to be notified).
Reference: http://www.cisco.com/warp/public/473/146.html#agree
QUESTION 53
On a PassGuide bridge running the Rapid Spanning-tree protocol (RSTP), BPDU
information on the port will be aged when?
A. After MaxAge time
B. 15 seconds
C. RSTP does not age out BPDU information on ports
D. After BPDU Age will reach MaxAge or after 3 hello times -which ever occurs first
E. After 6 seconds
F. None of the above
Answer: D
Explanation:
On a given port, if hellos are not received for three consecutive times, protocol
information can be immediately aged out (or if max_age expires). Because of the
350-001
www.actualtest.org – The Power of Knowing
previously mentioned protocol modification, BPDUs are now used as a keep-alive
mechanism between bridges. A bridge considers that it has lost connectivity to its direct
neighboring root or designated bridge if it misses three BPDUs in a row. This fast aging
of the information allows quick failure detection. If a bridge fails to receive BPDUs from
a neighbor, it is certain that the connection to that neighbor has been lost, as opposed to
802.1d where the problem could have been anywhere on the path to the root.
Reference:
http://www.cisco.com/en/US/partner/tech/ CK3 89/ CK6 21/technologies_white_paper09186a0080094cfa.shtml
QUESTION 54
The PassGuide network is experiencing network connectivity problems soon after an
end-user disconnected her PC and connects a switch with an unknown configuration
into an access layer switch port, which has spanning-tree portfast configured. What
should be configured on the access layer PassGuide switch to prevent these network
connectivity problems? (Select two)
A. PassGuide 2950(config-if)# spanning-tree portfast bpdufilter enable
B. PassGuide 2950(config-if)# spanning-tree portfast bpduguard enable
C. PassGuide 2950(config-if)# no spanning-tree portfast
D. PassGuide 2950(config-if)# spanning-tree link-type point-to-point
E. PassGuide 2950(config-if)# spanning-tree link-type shared
F. PassGuide 2950(config)# no spanning-tree backbonefast
G. PassGuide 2950(config)# no spanning-tree uplinkfast
Answer: B, C
Explanation:
The following explains the portfast Bridge Protocol Data Unit (BPDU) guard feature.
This feature is one of the Spanning-Tree Protocol (STP) enhancements created by Cisco
to enhance switch network reliability, manageability, and security.
STP configures a meshed topology into a loop-free, tree-like topology. When the link on
a bridge port goes up, there is STP calculation done on that port. The result of the
calculation will be the transition of the port into forwarding or blocking state, depending
on the position of the port in the network, and the STP parameters. This calculation and
transition period usually takes about 30-50 seconds. At this time, no user data is passing
via the port. Some user applications may timeout during this period.
To allow immediate transition of the port into forwarding state, the STP portfast feature
is enabled. Portfast transitions the port into STP forwarding mode immediately upon
linkup. The port still participates in STP in the event that if the port is to be a part of the
loop, it will eventually transition into STP blocking mode.
As long as the port is participating in STP, there is a possibility that some device attached
to that port and also running STP with lower bridge priority than that of the current root
bridge, will assume the root bridge function and affect active STP topology, thus
rendering the network suboptimal. Permanent STP recalculation caused by the temporary
introduction and subsequent removal of STP devices with low (zero) bridge priority
represent a simple form of Denial of Service (DoS) attack on the network.
350-001
www.actualtest.org – The Power of Knowing
The STP portfast BPDU guard enhancement is designed to allow network designers to
enforce the STP domain borders and keep the active topology predictable. The devices
behind the ports with STP portfast enabled are not allowed to influence the STP
topology. This is achieved by disabling the port with portfast configured upon reception
of BPDU. The port is transitioned into errdisable state, and a message is printed on the
console. This is done via the use of the “spanning-tree portfast bpduguard enable”
command.
Reference:
http://www.cisco.com/en/US/tech/ CK3 89/ CK6 21/technologies_tech_note09186a008009482f.shtml
QUESTION 55
On the PassGuide switched LAN, which of the following are true regarding Unidirectional
Link Detection (UDLD)? (Choose all that apply.)
A. UDLD uses auto-negotiation to take care of physical signaling and fault detection.
B. Both devices on the link need to support Unidirectional Link Detection.
C. It works by exchanging protocol packets between the neighboring devices.
D. It performs tasks that autonegotiation cannot perform.
E. UDLD is a layer one protocol.
Answer: A, B, C, and D