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NEW QUESTION # 31
In RSTP, which three port roles are associated with the discarding state? (Choose three.)
- A. root
- B. disabled
- C. alternate
- D. designated
- E. backup
Answer: B,C,E
Explanation:
Explanation
In Rapid Spanning Tree Protocol (RSTP), there are several port roles that determine the behavior of the port in the spanning tree123. The roles include root, designated, alternate, backup, and disabled123.
The discarding state is associated with the backup, alternate, and disabled roles123. In a stable topology with consistent port roles throughout the network, RSTP ensures that every root port and designated port immediately transition to the forwarding state while all alternate and backup ports are always in the discarding state2. Disabled ports are also in the discarding state3.
Therefore, options B, C, and D are correct.
NEW QUESTION # 32
Exhibit.
The ispi _ inet. 0 route table has currently no routes in it.
What will happen when you commit the configuration shown on the exhibit?
- A. The ISPI . inet. 0 route table will be completely overwritten by the inet. o route table.
- B. The inet. 0 route table will be imported into the ispi . inet. 0 route table.
- C. The inet. 0 route table will be completely overwritten by the ispi . inet. 0 route table.
- D. The ISPI . inet. 0 route table will be imported into the inet. 0 route table.
Answer: B
Explanation:
Explanation
The configuration shown in the exhibit is an example of a routing instance of type virtual-router. A routing instance is a collection of routing tables, interfaces, and routing protocol parameters that create a separate routing domain on a Juniper device1. A virtual-router routing instance allows administrators to divide a device into multiple independent virtual routers, each with its own routing table2.
The configuration also includes a rib-group statement, which is used to import routes from one routing table to another. A rib-group consists of an import-rib statement, which specifies the source routing table, and an export-rib statement, which specifies the destination routing table.
In this case, the rib-group name is inet-to-ispi, and the import-rib statement specifies inet.0 as the source routing table. The export-rib statement specifies ispi.inet.0 as the destination routing table. This means that the routes from inet.0 will be imported into ispi.inet.0.
Therefore, the correct answer is B. The inet.0 route table will be imported into the ispi.inet.0 route table.
References:
1: Routing Instances Overview 2: Virtual Routing Instances : [rib-group (Routing Options)]
NEW QUESTION # 33
You are configuring an IS-IS IGP network and do not see the IS-IS adjacencies established. In this scenario, what are two reasons for this problem? (Choose two.)
- A. The Level 2 routers have mismatched areas.
- B. MTU is not at least 1492 bytes.
- C. The lo0 interface is not included as an IS-IS interface.
- D. IP subnets are not a /30 address.
Answer: B,C
Explanation:
Explanation
Option A suggests that the MTU is not at least 1492 bytes. This is correct because IS-IS requires a minimum MTU of 1492 bytes to establish adjacencies1. If the MTU is less than this, IS-IS adjacencies will not be established1.
Option D suggests that the lo0 interface is not included as an IS-IS interface. This is also correct because the loopback interface (lo0) is typically used as the router ID in IS-IS1. If the loopback interface is not included in IS-IS, it could prevent IS-IS adjacencies from being established1.
Therefore, options A and D are correct.
NEW QUESTION # 34
Which two mechanisms are part of building and maintaining a Layer 2 bridge table? (Choose two.)
- A. listening
- B. learning
- C. blocking
- D. flooding
Answer: B,D
Explanation:
Option B is correct. Flooding is a mechanism used in Layer 2 bridging where the switch sends incoming packets to all its ports except for the port where the packet originated1. This is done when the switch doesn't know the destination MAC address or when the packet is a broadcast or multicast1.
Option C is correct. Learning is another mechanism used in Layer 2 bridging where the switch learns the source MAC addresses of incoming packets and associates them with the port on which they were received23. This information is stored in a MAC address table, also known as a bridge table23.
Option A is incorrect. Blocking is a state in Spanning Tree Protocol (STP) used to prevent loops in a network2. It's not a mechanism used in building and maintaining a Layer 2 bridge table2.
Option D is incorrect. Listening is also a state in Spanning Tree Protocol (STP) where the switch listens for BPDUs to make sure no loops occur in the network before transitioning to the learning state2. It's not a mechanism used in building and maintaining a Layer 2 bridge table2.
NEW QUESTION # 35
Exhibit.
What is the management IP address of the device shown in the exhibit?
- A. 172.23.11.10
- B. 128.0.0.1
- C. 10.210.20.233
- D. 172.23.12.100
Answer: D
Explanation:
Explanation
The management IP address of a device is the IP address that is used to access the device for configuration and monitoring purposes. It is usually assigned to a dedicatedmanagement interface that is separate from the data interfaces. The management interface can be accessed via SSH, Telnet, HTTP, or other protocols.
In the exhibit, the list of interfaces and their statuses shows that the management interface isme0. This interface has an admin status ofup, a protocol status ofinet, a local address of172.23.12.100/24, and a remote address ofunspecified. This means that the me0 interface is active, has an IPv4 address assigned, and is not connected to another device.
Therefore, the management IP address of the device shown in the exhibit is172.23.12.100.
References:
[Management Interfaces Overview] : [Displaying Interface Status Information]
NEW QUESTION # 36
You are concerned about spoofed MAC addresses on your LAN.
Which two Layer 2 security features should you enable to minimize this concern? (Choose two.)
- A. DHCP snooping
- B. static ARP
- C. dynamic ARP inspection
- D. IP source guard
Answer: A,C
Explanation:
A is correct because dynamic ARP inspection (DAI) is a Layer 2 security feature that prevents ARP spoofing attacks. ARP spoofing is a technique that allows an attacker to send fake ARP messages to associate a spoofed MAC address with a legitimate IP address. This can result in traffic redirection, man-in-the-middle attacks, or denial-of-service attacks. DAI validates ARP packets by checking the source MAC address and IP address against a trusted database, which is usually built by DHCP snooping1. DAI discards any ARP packets that do not match the database or have invalid formats1.
C is correct because DHCP snooping is a Layer 2 security feature that prevents DHCP spoofing attacks.
DHCP spoofing is a technique that allows an attacker to act as a rogue DHCP server and offer fake IP addresses and other network parameters to unsuspecting clients. This can result in traffic redirection, man-in-the-middle attacks, or denial-of-service attacks. DHCP snooping filters DHCP messages by classifying switch ports as trusted or untrusted. Trusted ports are allowed to send and receive any DHCP messages, while untrusted ports are allowed to send only DHCP requests and receive only valid DHCP replies from trusted ports2. DHCP snooping also builds a database of MAC addresses, IP addresses, lease times, and binding types for each client2.
NEW QUESTION # 37
You want to ensure traffic is routed through a GRE tunnel.
In this scenario, which two statements will satisfy this requirement? (Choose two.)
- A. All intermediary devices must have a route to the tunnel endpoints.
- B. Tunnel endpoints must have a route that directs traffic into the tunnel.
- C. BFD must be used on the stateless tunneling protocols.
- D. Keepalives must be used on stateless tunneling protocols.
Answer: A,B
Explanation:
Explanation
Option A is correct. For traffic to be sent through a GRE tunnel, there must be a route that directs the traffic into the tunnel. This is typically accomplished through the use of a static route or a dynamic routing protocol.
Option B is correct. All intermediary devices must have a route to the tunnel endpoints34. In real-world scenarios, the tunnel endpoints for a tunnel going over the Internet must have globally reachable internet addresses. Otherwise, intermediate routers in the Internet cannot forward the tunneled packets.
NEW QUESTION # 38
You are troubleshooting a BGP routing issue between your network and a customer router and are reviewing the BGP routing policies. Which two statements are correct in this scenario? (Choose two.)
- A. Export policies are applied after the RIB-Local table.
- B. Import policies are applied to routes in the RIB-Local table.
- C. Export policies are applied to routes in the RIB-ln table.
- D. Import policies are applied after the RIB-ln table.
Answer: A,D
Explanation:
Explanation
In BGP, routing policies are used to control the flow of routing information between BGP peers1.
Option C suggests that import policies are applied after the RIB-In table. This is correct because import policies in BGP are applied to routes that are received from a BGP peer, before they are installed in the local BGP Routing Information Base (RIB-In)1. The RIB-In is a database that stores all the routes that are received from all peers1.
Option D suggests that export policies are applied after the RIB-Local table. This is correct because export policies in BGP are applied to routes that are being advertised to a BGP peer, after they have been selected from the local BGP Routing Information Base (RIB-Local)1. The RIB-Local is a database that stores all the routes that the local router is using1.
Therefore, options C and D are correct.
NEW QUESTION # 39
What are two characteristics of RSTP alternate ports? (Choose two.)
- A. RSTP alternate ports block traffic while receiving superior BPDUs from a neighboring switch.
- B. RSTP alternate ports are active ports used to forward frames toward the root bridge.
- C. RSTP alternate ports provide an alternate higher cost path to the root bridge.
- D. RSTP alternate ports provide an alternate lower cost path to the root bridge.
Answer: A,C
Explanation:
A is correct because RSTP alternate ports block traffic while receiving superior BPDUs from a neighboring switch. An alternate port is a backup port for a root port, which means it receives better BPDUs from another bridge than the current root port1. However, an alternate port does not forward any traffic, as it is in a discarding state2. It only listens to BPDUs and waits for the root port to fail. If the root port fails, the alternate port can immediately transition to a forwarding state and become the new root port1.
C is correct because RSTP alternate ports provide an alternate higher cost path to the root bridge. An alternate port is selected based on the same criteria as the root port, which are the lowest bridge ID, the lowest path cost, the lowest sender port ID, and the lowest receiver port ID3. However, an alternate port receives a higher cost BPDU than the root port, otherwise it would be the root port itself1. Therefore, an alternate port provides an alternate higher cost path to the root bridge than the root port.
NEW QUESTION # 40
What is the default MAC age-out timer on an EX Series switch?
- A. 30 seconds
- B. 30 minutes
- C. 300 seconds
- D. 300 minutes
Answer: C
Explanation:
Explanation
The default MAC age-out timer on an EX Series switch is 300 seconds12. The MAC age-out timer is the maximum time that an entry can remain in the MAC table before it "ages out," or is removed31. This configuration can influence efficiency of network resource use by affecting the amount of traffic that is flooded to all interfaces1. When traffic is received for MAC addresses no longer in the Ethernet routing table, the router floods the traffic to all interfaces1.
NEW QUESTION # 41
Which two statements correctly describe RSTP port roles? (Choose two.)
- A. The alternate port is a standby port for an edge port.
- B. The designated port forwards data to the downstream network segment or device.
- C. The backup port is used as a backup for the root port.
- D. The root port is responsible for forwarding data to the root bridge.
Answer: B,D
Explanation:
Explanation
In Rapid Spanning Tree Protocol (RSTP), there are several port roles that determine the behavior of the port in the spanning tree1.
Option A suggests that the designated port forwards data to the downstream network segment or device. This is correct because the designated port is the port on a network segment that has the best path to the root bridge1. It's responsible for forwarding frames towards the root bridge and sending configuration messages into its segment1.
Option D suggests that the root port is responsible for forwarding data to the root bridge. This is also correct because the root port is always the link directly connected to the root bridge, or the shortest path to the root bridge1. It's used to forward traffic towards the root bridge1.
Therefore, options A and D are correct.
NEW QUESTION # 42
You want to use filter-based forwarding (FBF) on your Internet peering router to load-balance traffic to two directly connected ISPs based on the source address.
Which two statements are correct in this scenario? (Choose two.)
- A. RIB groups are used to copy routes from the inet. o routing table.
- B. FBF uses the no-forwarding routing instance type.
- C. FBF uses the forwarding routing instance type.
- D. RIB groups are used to hide routes in the inet. 0 routing table.
Answer: A,C
Explanation:
Option B is correct. Filter-based forwarding (FBF), also known as Policy Based Routing (PBR), uses the forwarding routing instance type12.
Option C is correct. Routing Information Base (RIB) groups are used to copy routes from one routing table to another34. In the context of FBF, RIB groups can be used to copy routes from the inet.0 routing table34.
Option A is incorrect. FBF does not use the no-forwarding routing instance type15.
Option D is incorrect. RIB groups are not used to hide routes in the inet.0 routing table34. They are used to share or copy routes between different routing tables34.
NEW QUESTION # 43
Exhibit.
Why is this OSPF adjacency remaining in this state?
- A. An area ID mismatch exists between the OSPF neighbors
- B. A subnet mask mismatch exists between the OSPF neighbors.
- C. An MTU mismatch exists between the OSPF neighbors.
- D. A hello interval mismatch exists between the OSPF neighbors.
Answer: C
Explanation:
The exhibit shows the output of the command , which displays information about the OSPF neighbors on a router1.
The output shows that the OSPF neighbor with the address 172.26.1.1 and the interface ge-0/0/3.0 is in the Exstart state1.
The Exstart state is the fourth state in the OSPF neighbor formation process, after Down, Init, and
2-Way states2. In this state, the OSPF neighbors establish a master-slave relationship and exchange database description (DBD) packets, which contain summaries of their link-state databases2.
The most common reason for OSPF neighbors to be stuck in the Exstart state is an MTU mismatch between the interfaces3. MTU stands for maximum transmission unit, which is the largest size of a packet that can be transmitted on a network segment4. If the MTU values of two OSPF neighbors are different, theymay not be able to exchange DBD packets successfully, as some packets may be dropped or fragmented due to their size exceeding the MTU limit3.
To solve this problem, you need to ensure that the MTU values of both OSPF neighbors are the same or compatible. You can use the command show interfaces to display the MTU value of an interface5. You can also use the command ping with the do-not-fragment option to test the MTU size between two routers. You can change the MTU value of an interface by using the command set interfaces interface-name mtu mtu-value in configuration mode5.
NEW QUESTION # 44
Which two events cause a router to advertise a connected network to OSPF neighbors? (Choose two.)
- A. When a static route to the 224.0.0.6 address is created.
- B. When an interface has the OSPF passive option enabled.
- C. When a static route to the 224.0.0.5 address is created.
- D. When an OSPF adjacency is established.
Answer: C,D
Explanation:
A is correct because when an OSPF adjacency is established, a router will advertise a connected network to OSPF neighbors. An OSPF adjacency is a logical relationship between two routers that agree to exchange routing information using the OSPF protocol1. To establish an OSPF adjacency, the routers must be in the same area, have compatible parameters, and exchange hello packets1. Once an OSPF adjacency is formed, the routers will exchange database description (DBD) packets, which contain summaries of their link-state databases (LSDBs)1. The LSDBs include information about the connected networks and their costs2. Therefore, when an OSPF adjacency is established, a router will advertise a connected network to OSPF neighbors through DBD packets.
D is correct because when a static route to the 224.0.0.5 address is created, a router will advertise a connected network to OSPF neighbors. The 224.0.0.5 address is the multicast address for all OSPF routers3. A static route to this address can be used to send OSPF hello packets to all OSPF neighbors on a network segment3. This can be useful when the network segment does not support multicast or when the router does not have an IP address on the segment3. When a static route to the 224.0.0.5 address is created, the router will send hello packets to this address and establish OSPF adjacencies with other routers on the segment3. As explained above, once an OSPF adjacency is formed, the router will advertise a connected network to OSPF neighbors through DBD packets.
NEW QUESTION # 45
Exhibit
Your BGP neighbors, one in the USA and one in France, are not establishing a connection with each other.
Referring to the exhibit, which statement is correct?
- A. The BFD liveness must be configured on the BGP group.
- B. The BFD liveness is set too low.
- C. The BFD liveness must be configured on the BGP neighbor.
- D. The BFD liveness is set too high.
Answer: C
Explanation:
Explanation
The exhibit shows the configuration of BFD liveness detection for BGP at the global level, which applies to all BGP neighbors by default1. However, this configuration does not specify the session mode, which determines whether BFD uses single-hop or multihop mode to communicate with a neighbor2.
For single-hop BGP neighbors, which are directly connected on the same subnet, the session mode can be either automatic or single-hop. For multihop BGPneighbors, which are not directly connected and require multiple hops to reach, the session mode must be multihop2.
Since your BGP neighbors are in different countries, they are likely to be multihop neighbors. Therefore, you need to configure the session mode as multihop for each neighbor individually at the [edit protocols bgp group group-name neighbor address bfd-liveness-detection] hierarchy level2. For example:
protocols { bgp { group usa { neighbor 192.0.2.1 { bfd-liveness-detection { session-mode multihop; } } } group france { neighbor 198.51.100.1 { bfd-liveness-detection { session-mode multihop; } } } } } If you do not configure the session mode for multihop neighbors, BFD will use the default mode of automatic, which will try to use single-hop mode and fail to establish a BFD session with the remote neighbor2. This will prevent BGP from using BFD to detect liveliness and failover.
Therefore, the answer B is correct, as you need to configure the BFD liveness detection on the BGP neighbor level with the appropriate session mode for multihop neighbors.
NEW QUESTION # 46
Exhibit.
You are using OSPF to advertise the subnets that are used by the Denver and Dallas offices. The routers that are directly connected to the Dallas and Denver subnets are not advertising the connected subnets.
Referring to the exhibit, which two statements are correct? (Choose two.)
- A. Configure and apply a routing policy that redistributes the Dallas and Denver subnets using Type 5 LSAs.
- B. Create static routes on the switches using the local vMX router's loopback interface for the next hop.
- C. Enable the passive option on the OSPF interfaces that are connected to the Dallas and Denver subnets.
- D. Configure and apply a routing policy that redistributes the connected Dallas and Denver subnets.
Answer: C,D
Explanation:
Explanation
The routers that are directly connected to the Dallas and Denver subnets are not advertising the connected subnets. This can be resolved by redistributing the connected subnets into OSPF1.
Option C suggests to configure and apply a routing policy that redistributes the connected Dallas and Denver subnets. This is correct because redistribution allows routes from one routing protocol to be communicated to another, and in this case, it allows the connected subnets to be advertised through OSPF1.
Option D suggests enabling the passive option on the OSPF interfaces that are connected to the Dallas and Denver subnets. This is also correct because in OSPF, a passive interface is an interface that belongs to the OSPF router, but does not send OSPF Hello packets1. It's typically used on an interface that you don't want to use for OSPF adjacencies, but you still want to advertise its IP address1. Therefore, enabling passive interface can help in advertising the Dallas and Denver subnets.
NEW QUESTION # 47
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