2014 Latest Cisco 350-001 Dump Free Download(181-190)!
IEEE 802.1w is a Rapid Spanning Tree Protocol (RSTP) that can be seen as an evolution of the
802.1 standard. What are the port roles described by 802.1w?
A. root port, designated port, alternate port, backup port, and disabled
B. standby port, alternate port, root port, and disabled
C. standby port, designated port, backup port, and disabled
D. root port, designated port, alternate port, and standby port
The role is now a variable assigned to a given port. The root port and designated port roles remain, while the blocking port role is split into the backup and alternate port roles. The Spanning Tree Algorithm (STA) determines the role of a port based on Bridge Protocol Data Units (BPDUs). In order to simplify matters, the thing to remember about a BPDU is there is always a method to compare any two of them and decide whether one is more useful than the other. This is based on the value stored in the BPDU and occasionally on the port on which they are received.
Root Port Roles
The port that receives the best BPDU on a bridge is the root port. This is the port that is the closest to the root bridge in terms of path cost. The STA elects a single root bridge in the whole bridged network (per-VLAN). The root bridge sends BPDUs that are more useful than the ones any other bridge sends. The root bridge is the only bridge in the network that does not have a root port. All other bridges receive BPDUs on at least one port.
A port is designated if it can send the best BPDU on the segment to which it is connected. 802.1D bridges link together different segments, such as Ethernet segments, to create a bridged domain. On a given segment, there can only be one path toward the root bridge. If there are two, there is a bridging loop in the network. All bridges connected to a given segment listen to the BPDUs of each and agree on the bridge that sends the best BPDU as the designated bridge for the segment. The port on that bridge that corresponds is the designated port for that segment.
Alternate and Backup Port Roles
These two port roles correspond to the blocking state of 802.1D. A blocked port is defined as not being the designated or root port. A blocked port receives a more useful BPDU than the one it sends out on its segment.
Remember that a port absolutely needs to receive BPDUs in order to stay blocked. RSTP introduces these two roles for this purpose.
An alternate port receives more useful BPDUs from another bridge and is a port blocked. A backup port receives more useful BPDUs from the same bridge it is on and is a port blocked. This distinction is already made internally within 802.1D. This is essentially how Cisco UplinkFast functions.
The rationale is that an alternate port provides an alternate path to the root bridge and therefore can replace the root port if it fails. Of course, a backup port provides redundant connectivity to the same segment and cannot guarantee an alternate connectivity to the root bridge. Therefore, it is excluded from the uplink group.
As a result, RSTP calculates the final topology for the spanning tree that uses the same criteria as 802.1D.
There is absolutely no change in the way the different bridge and port priorities are used. The name blocking is used for the discarding state in Cisco implementation. CatOS releases 7.1 and later still display the listening and learning states. This gives even more information about a port than the IEEE standard requires. However, the new feature is now there is a difference between the role the protocol determines for a port and its current state. For example, it is now perfectly valid for a port to be designated and blocking at the same time. While this typically occurs for very short periods of time, it simply means that this port is in a transitory state towards the designated forwarding state.
This question is about the Spanning Tree Protocol (STP) root guard feature. What is the STP root guard feature designed to prevent?
A. a root port being transitioned to the blocking state
B. a port being assigned as a root port
C. a port being assigned as an alternate port
D. a root port being transitioned to the forwarding state
As a network engineer, you responsibility is to install, configure, operate, and troubleshoot
networks. In your company’s network, EIGRP is the routing protocol. You have just discovered
that two routers restarted the neighbor relationship. Why? (Select two.)
A. An update packet with init flag set from a known, already established neighbor relationship was
received by one of the routers.
B. The counters were deleted.
C. The ARP cache was removed.
D. The IP EIGRP neighbor relationship was cleared manually.
Which two statements are true about the role of split horizon? (Choose two.)
A. It is a function used by routing protocols to install routes into routing table
B. It is a function that prevents the advertising of routes over an interface that the router is using
to reach a route
C. Its function is to help avoid routing loops.
D. It is a redistribution technique used by routing protocols
Split horizon is a method of preventing a routing loop in a network. The basic principle is simple:
Information about the routing for a particular packet is never sent back in the direction from which it was received.
Split horizon can be achieved by means of a technique called poison reverse. This is the equivalent of route poisoning all possible reverse paths – that is, informing all routers that the path back to the originating node for a particular packet has an infinite metric. Split horizon with poison reverse is more effective than simple split horizon in networks with multiple routing paths, although it affords no improvement over simple split horizon in networks with only one routing path.
Which statement best describes OSPF external LSAs (type 5)?
A. OSPF external LSAs are automatically flooded into all OSPF areas, unlike type 7 LSAs, which
require that redistribution be configured.
B. External LSAs (type 5) are automatically changed to type 1 LSAs at ASBRs.
C. Type 5 LSAs are route summaries describing routes to networks outside the OSPF Autonomous
D. External network LSAs (type 5) redistributed from other routing protocols into OSPF are not
permitted to flood into a stub area
Type 5 – External LSA – these LSAs contain information imported into OSPF from other routing processes.
They are flooded to all areas (except stub areas). For “External Type 1” LSAs routing decisions are made by adding the OSPF metric to get to the ASBR and the external metric from there on, while for “External Type 2” LSAs only the external metric is used. The link-state ID of the type 5 LSA is the external network number
This question is about the formation of OSPF adjacency. An OSPF adjacency will not form
correctly across a point-to-point link in the same area. Which would most likely cause this
A. Each interface has a different OSPF cost.
B. Each interface is configured with secondary addresses as well as primary addresses.
C. Each interface has a different MTU size.
D. Each interface is configured with the ip unnumbered loopback 0 command.
http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a0080093f0e.shtml Cisco General Networking Theory Quick Reference Sheets
Which two statements best describe CBWFQ? (Choose two.)
A. The CBWFQ scheduler provides a guaranteed minimum amount of bandwidth to each class.
B. CBWFQ services each class queue using a strict priority scheduler.
C. The class-default queue only supports WFQ.
D. Inside a class queue, processing is always FIFO, except for the class-default queue.
Which statement is true of a source that wants to transmit multicast traffic to group 184.108.40.206?
A. Before sending traffic, it must first join multicast group 220.127.116.11 by sending an IGMPv2
membership report to the default router on the local subnet.
B. It must send an IGMPv2 Request to Send packet and then wait for an IGMPv2 Clear to Send
packet from the IGMPv2 querier router on the local subnet
C. It may begin transmitting multicast traffic to the group only when there is no other host transmitting
to the group on the local subnet.
D. It may transmit multicast traffic to the group at any time.
IP multicast is a method of sending Internet Protocol (IP) datagrams to a group of interested receivers in a single transmission. It is often employed for streaming media applications on the Internet and private networks.
The method is the IP-specific version of the general concept of multicast networking. It uses specially reserved multicast address blocks in IPv4 and IPv6. In IPv6, IP multicast addressing replaces broadcast addressing as implemented in IPv4.
Key concepts in IP multicast include an IP multicast group address, a multicast distribution tree and receiver driven tree creation.
An IP multicast group address is used by sources and the receivers to send and receive multicast messages. Sources use the group address as the IP destination address in their data packets. Receivers use this group address to inform the network that they are interested in receiving packets sent to that group. For example, if some content is associated with group 18.104.22.168, the source will send data packets destined to 22.214.171.124. Receivers for that content will inform the network that they are interested in receiving data packets sent to the group 126.96.36.199. The receiver joins 188.8.131.52. The protocol typically used by receivers to join a group is called the Internet Group Management Protocol (IGMP).
With routing protocols based on shared trees, once the receivers join a particular IP multicast group, a multicast distribution tree is constructed for that group. The protocol most widely used for this is Protocol Independent Multicast (PIM). It sets up multicast distribution trees such that data packets from senders to a multicast group reach all receivers which have joined the group. For example, all data packets sent to the group 184.108.40.206 are received by receivers who joined 220.127.116.11. There are variations of PIM implementations: Sparse Mode (SM), Dense Mode (DM), Source Specific Mode (SSM) and Bidirectional Mode (Bidir, or Sparse-Dense Mode, SDM). Of these, PIM-SM is the most widely deployed as of 2006; SSM and Bidir are simpler and scalable variations developed more recently and are gaining in popularity.
Which two statements are true about 802.1s? (Choose two.)
A. 802.1s supports a reduced number of spanning-tree instances.
B. 802.1s has better convergence times than 802.1w.
C. 802.1s does not support load balancing over the same physical topology.
D. The CPU utilization for 802.1s is lower than the CPU utilization for 802.1w.
Which configuration is used to enable root guard?
A. interface gig3/1
spanning-tree guard root
B. interface gig3/1
spanning-tree root guard
C. interface gig3/1
D. interface gig3/1
spanning-tree root-guard default
If you want to pass the Cisco 350-001 Exam sucessfully, recommend to read latest Cisco 350-001 Dump full version.