CCNA 3 v5.1 + v6.0 Practice Final Test Online 2018-2019

Hint

Besides the VTP domain name and mode needing to be configured, the switch must connect to other switches in the same VTP domain through a trunk in order to transmit/receive VTP information.

Hint

The AS number identifies the EIGRP routing process, and multiple AS numbers can be configured on a router to facilitate multiple EIGRP processes running on a network. The AS number is not associated with the global Autonomous System number that is assigned by IANA, because EIGRP is an interior gateway protocol. The reliability of EIGRP and the priority of networks that are included in updates are not linked to AS numbers.

Hint

The root bridge is determined by the lowest bridge ID, which consists of the priority value and the MAC address. Because the priority values of all of the switches are identical, the MAC address is used to determine the root bridge. Because S2 has the lowest MAC address, S2 becomes the root bridge.

Hint

In PVST+ configuration, the spanning-tree vlan vlan-id root primary global configuration mode command will set the priority for the switch to the predefined value of 24,576 or to the highest multiple of 4,096, less than the lowest bridge priority detected on the network. The spanning-tree vlan vlan-id root secondary global configuration mode command will set the priority for the switch to the predefined value of 28,672. Because S1 is configured with the priority value of 12,288 for VLAN 30, S3 has to be configured with the priority value of 8,192 (highest multiple of 4,096 but lower than 12,288) to become the root bridge for VLAN 30.

Hint

To establish adjacency, both routers must be configured with the same AS number. The network 192.168.0.0 .0.0.255.255 command issued on R1 includes all networks from 192.168.0.0 to 192.168.255.255. Therefore, the network 192.168.1.0/24 is also included.

Hint

OSPF neighbor adjacencies are formed using the link-local address of the interfaces that are connecting to neighboring routers.

Hint

OSPF type 2 LSAs are only flooded on multiaccess and NBMA networks where a designated router is elected. The type 2 LSA is created by the designated router and advertises the router ID of the designated router to other OSPF routers.

Hint

Different routing protocols uses different metrics to calculate the best path through the routed network. RIP uses hop count, EIGRP uses bandwidth and delay, and OSPF uses cost.

Hint

By default, EIGRP is able to use up to 50 percent of the bandwidth on an interface for EIGRP messages.

Hint

Spanning Tree Protocol (STP) supports the design of a scalable network by preventing Layer 2 loops where redundant switch paths are implemented.

Hint

All OSPFv3 messages are sourced from the link-local IPv6 address of an interface. Link local addresses use the prefix FE80::/10.

Hint

The wildcard mask can be found by subtracting the subnet mask from 255.255.255.255.

Hint

In order to form OSPFv2 neighbor adjacencies, two connected router interfaces must share the same subnet. Router R2 is shown in the topology with an IP address of 192.168.20.5 and does not exist on the same subnet as the 192.168.20.1 /30 IP address of S0/0 on router R1.

Hint

The OSPF priority can be set to a number between 0 and 255. The higher the number set, the more likely the router becomes the DR. A priority 0 stops a router from participating in the election process and the router does not become a DR or a BDR.

Hint

The no switchport command allows a switch port to be assigned an IP address. The port is a routed port at that point. The ip routing command enables routing for a switch. Use the interface vlan x command on the switch to configure routing for any VLAN that is attached to the switch, including the management VLAN. No management VLAN is shown in this scenario, but the commands interface vlan 5 and interface vlan 6, along with an appropriate IP address and subnet mask for each VLAN, would be used on the switch in the exhibit. There is no need to add an IP address or use the no shutdown command on VLAN 1 because VLAN 1 is not used in this design and because VLAN 1 is “up and up” by default.

Hint

With the show ip eigrp neighbors command, the output includes: H column – Lists the neighbors in the order that they were learned. Address – IPv4 address of the neighbor. Interface – Local interface on which this Hello packet was received. Hold – Current hold time. When a Hello packet is received, this value is reset to the maximum hold time for that interface, and then counts down to zero. If zero is reached, the neighbor is considered down. Queue Count – Should always be zero. If more than zero, then EIGRP packets wait to be sent. In the output shown, the neighbor router with IP 10.10.10.2 was the first neighbor learned by router R1.

Hint

The maximum-paths command is used to configure equal-cost load balancing with EIGRP. The variance command is used to configure unequal-cost load balancing, but the default variance is 1. If the variance is set to 1, only routes with the same metric as the successor are installed in the local routing table. So, to configure unequal-cost load balancing, the variance 2 command should be used.

Hint

The command output shows the port channel as SU, which means Layer 2 and in use; and the FastEthernet 0/10 and 0/11 interfaces are bundled in port-channel as indicated by the P flag. Configuring the EtherChannel using the channel-group 1 mode on command will cause the Protocol field in the command output to be empty.

Hint

EtherChannel technology allows the grouping, or aggregating, of several Fast Ethernet or Gigabit switch ports into one logical channel.

Hint

Both versions of OSPF use the same five basic packet types, the cost metric, and the DR/BDR election process. Hello packets are used in both versions to build adjacencies. OSPFv3, however, uses advanced encryption and authentication features that are provided by IPsec, while OSPFv2 uses either plain text or MD5 authentication.

Hint

All interfaces in the EtherChannel bundle must be assigned to the same VLAN or be configured as a trunk. If the allowed range of VLANs is not the same, the interfaces do not form an EtherChannel even when set to auto or desirable mode.

Hint

Interarea summarization is manually configured on Area Border Routers (ABRs). Because ABRs connect multiple areas, it is these routers that would summarize routes before injecting them into another area. ASBRs are configured with external route summarization. Backbone and intra-area routers have all interfaces in a single area and are not able to summarize routes into other areas.

Hint

When adding a new switch to a VTP domain, it is critical to configure the switch with a new domain name, the correct VTP mode, VTP version number, and password. A switch with a higher revision number can propagate invalid VLANs and erase valid VLANs thus preventing connectivity for multiple devices on the valid VLANs.

Hint

In order to implement RIP, EIGRP, or OSPF, configuration begins by typing router protocol. An example would be router ospf 1. In IPv4, network statements are added for each directly connected network that is participating in the dynamic routing protocol. An example would be network 192.168.10.0 0.0.0.255 area 0.

Hint

By default, Fast Ethernet, Gigabit, and 10 Gigabit Ethernet interfaces all have a cost of 1. Altering the default reference bandwidth alters the cost calculation, allowing each speed to be more accurately reflected in the cost.

Hint

LACP, or Link Aggregation Control Protocol, is defined by IEEE 802.3ad and is an open standard protocol. LACP allows switches to automatically bundle switch ports into a single logical link to increase bandwidth. PAgP, or Port Aggregation Protocol, performs a similar function, but it is a Cisco proprietary protocol. DTP is Dynamic Trunking Protocol and is used to automatically and dynamically build trunks between switches. Multilink PPP is used to load-balance PPP traffic across multiple serial interfaces.

Hint

According to the configuration shown, the router was configured to use the wrong VLAN (500 instead of 50) on subinterface Fa0/0.50. This will prevent devices that are configured on VLAN 50 from communicating with subinterface Fa0/0.50. When configuring subinterfaces, the Fa0/0 interface has to be configured with no IP address, and each subinterface has to be assigned to a different subnet.

Hint

The output indicates that the K values are in default (K1=1, K2=0, K3=1, K4=0, K5=0). The no auto-summary command is used since automatic summarization is not in effect. R1 is advertising the 192.168.1.0 and 10.0.0.0 networks, not receiving advertisements about them. Up to 4 equal metric paths to the same destination network will be included in the routing table since the metric variance parameter is set to 1.

Hint

Routed ports are physical ports that act similarly to a router interface. They are not associated with a particular VLAN, they do not support subinterfaces, and they are used for point-to-point links. In a switched network, they are mostly configured between switches at the core and distribution layers. To configure routed ports, the no switchport interface command has to be used on the appropriate ports.

Hint

One method of implementing redundancy is path redundancy, which means installing alternate physical paths for data to traverse the network. Redundant links in a switched network support high availability and can be used for load balancing, thus reducing congestion on the network.

Hint

If the priority is set to 0, the router is not capable of becoming the DR, so router A cannot be the DR. OSPF DR and BDR elections are not preemptive. If a new router with a higher priority or higher router ID is added to the network after the DR and BDR election, the newly added router does not take over the DR or the BDR role.​

Hint

The fact that some networks appear in the routing table of R2 indicates that there is basic EIGRP communication between R1 and R2. This excludes the possibility of AS number mismatch and the interface between R1 and R2 being passive. Hello interval timers between EIGRP routers do not have to match. The administrator needs to make sure that the network commands cover all networks attached to R1 that should be advertised.

Hint

EIGRP maintains a topology table that contains all of the routes learned from EIGRP neighbors. The routes will include successors and feasible successors.

Hint

The default route is applied to the router that connects to the Internet, or R0-A. R0-A then distributes that default route using the OSPF routing protocol.

Hint

In this example Router1 does not have a specific route to the172.16.4.0/24 network. Because the 172.16.4.0/24 network falls within the 172.16.0.0/18 summary network route to Null0, this route will be chosen. As a consequence, Router1 will drop the packets destined for the 172.16.4.0/24network. The reason for Router1 not using the default route is that the Null0 route has a longer matching network mask.

Hint

In a large enterprise network, the provision of a high-speed network backbone is a function of the core layer. Access layer switches connect users to the network and provide Power over Ethernet to devices. Distribution layer routers provide data traffic security and connections to other networks.

Hint

By default, k1 and k3 are set to one and k2, k4, and k5 are set to zero during cost calculation by the EIGRP process. There is no k6 value.

Hint

The three routers R1, R2 and R3 implement EIGRP as the routing protocol. There are two discontiguous networks with no connectivity between them. Automatic summarization is enabled by default on routers R1 and R2, and this is causing a routing problem between discontiguous networks. The solution is to issue the no auto-summary command on each router: R1(config)# router eigrp 100 R1(conf-router)# no auto-summary R2(config)# router eigrp 100 R2(conf-router)# no auto-summary After these commands are issued, PC1 is able to access the web server and the message displayed is “You’ve made it!”.

Hint

The full and 2way states are two stable OSPF adjacency types.

Hint

ASICs are application-specific integrated circuits and they allow a multilayer switch to forward IP packets without calling on the CPU to make routing decisions. By using ASICs a switch can forward IP packets almost as fast as it can forward Layer 2 frames.

Hint

The three VTP modes are server, client, and transparent. In server VTP mode, the switch can create, modify, and delete VLANs and send this information on to other switches that are in the same VTP domain. Switches in transparent VTP mode can do the same except that information is not transmitted to other switches.

Hint

IS-IS is a link state IGP routing protocol that supports classless routing. It is commonly used by ISPs and carriers.

Hint

The fact that R2 has a route to 172.18.100.0 from R1 indicates that EIGRP is functioning, which excludes the issue of an AS number not matching. The issue is that both sides have a network within the Class B 172.16.0.0/16 network. Therefore, automatic network summarization must be disabled by the no auto-summary command. If this command is not used, the network statement with a wild card mask will not have effect. The passive interface, if configured, will prevent EIGRP updates from entering the two networks, but not prevent R1 from advertising them to R2.

Hint

Type 5 LSAs are used for external routes and are generated by an ASBR. They are forwarded into other areas by ABRs.

Hint

Without ties between them, the elections took place based only on interface priorities.

Hint

n a routing table, the designation O IA means the entry was learned from an interarea LSA that was generated from an ABR. The C label indicates a network that is directly connected to an interface on the router. The O label indicates a network that is advertised by another router in the same area. The label O*E2 indicates an external network. In this case, the network designation of 0.0.0.0/0 indicates that this external network is the default route for all traffic that is destined for external networks.

Hint

Cisco switches support two protocols for negotiating a channel between two switches: LACP and PAgP. PAgP is Cisco-proprietary. In the topology shown, the switches are connected to each other using redundant links. By default, STP is enabled on switch devices. STP will block redundant links to prevent loops.

Hint

Two primary reasons for implementing passive interfaces in EIGRP routing are to suppress unnecessary update traffic, such as when an interface is a LAN interface with no other routers connected, and to increase security controls, such as preventing unknown rogue routing devices from receiving EIGRP updates.

Hint

Access layer switches are cheaper and do not have as many ports or features as the switches that work at the distribution or core layers. The number of ports that are needed depends on the number of wired devices in the area. Access layer switches tend to be fixed configuration switches that have a set number of ports. Ports on access layer switches tend to operate at 100 or 1000 Mb/s. Switches that operate at all three design layers are capable of EtherChannel and RSTP. The Catalyst 4500X model switch is used at the core design layer.

Hint

An OSPF router progresses in this order to convergence, using the following packets: 1. Hello packet, used for OSPF election and establishing neighbor adjacencies 2. DBD packet, used to synchronize databases with neighbors 3. LSR packet, used to request more information in synchronizing databases 4. LSU packet, used to send link-state updates to neighbors 5. LSAck packet, used to acknowledge receipt of an LSU

Hint

Because Rapid PVST+ is a Cisco enhancement of RSTP, it will support PortFast, BPDU guard, BPDU filter, root guard, and loop guard. Uplink fast and Backbone fast are incorporated into the protocol.

Hint

EIGRP avoids DUAL recomputation of routes whenever possible by maintaining a list of backup routes (feasible successors) in the topology table already determined to be loop-free. If the primary route (the successor route, which is in the passive state) in the routing table fails, the best backup route is immediately added to the routing table. A route in the active state is in the process of being recomputed by DUAL.

Hint

STP is an important component in a scalable network because it allows redundant physical connections between Layer 2 devices to be implemented without creating Layer 2 loops. STP prevents Layer 2 loops from forming by disabling interfaces on Layer 2 devices when they would create a loop.

Hint

EtherChannel is utilized on a network to increase speed capabilities by grouping multiple physical ports into one or more logical EtherChannel links between two switches. STP is used to provide redundant links that dynamically block or forward traffic between switches. FHRPs are used to group physical devices to provide traffic flow in the event of failure.

Hint

Even though PVST+ mode is Cisco proprietary, the command output shows as ieee. In Rapid-PVST mode, the command output shows as simply rstp.

Hint

Before EIGRP for IPv6 can be configured on a router, routing for IPv6 must be configured. This is accomplished by issuing the global configuration command ipv6 unicast-routing.

Hint

The show ip protocols command verifies whether automatic summarization is being used on the local router, whether any interfaces on the local router are configured as passive interfaces, whether a network is not advertised to EIGRP neighbors, and whether any ACLs are applied to EIGRP.

Hint

The maximum-paths command must be issued in the router configuration mode to load balance up to 32 routes.

Hint

Gateway Load Balancing Protocol (GLBP) provides load sharing between a group of redundant routers while also protecting data traffic from a failed router or circuit.