300-410 Online Practice Questions and Answers

Correct Answer: B

The set ip default next-hop command verifies the existence of the destination IP address in the routing table, and...

1.

if the destination IP address exists, the command does not policy route the packet, but forwards the packet based on the routing table.

2.

if the destination IP address does not exist, the command policy routes the packet by sending it to the specified next hop.

Correct Answer: B

The "transport output none" command prevents any protocol connection made from R1.

Therefore our SSH connection to 192.168.12.2 was refused. In order to fix this problem we can configure "transport output ssh" under "line console 0" of R1.

Note: The parameter "-l" specifies the username to log in as on the remote machine.

https://community.cisco.com/t5/other-network-architecture/out-of-band-router-access/td-p/333295

Correct Answer: A

Correct Answer: BC

Correct Answer: A

Correct Answer: D

Looking at the debug output, second to the last line, the log suggests that it is attempting to use server x.x.10.10 when the diagram specifies that the server is actually x.x.10.11.

This would require the tacacs group to be modified to use the correct server:

`tacacs server prod`

`address ipv4 x.x.10.11`

`exit`

Correct Answer: D

Correct Answer: D

The correct configuration to prevent Customer AS 111 from being used as a transit path on ISP-1 is option D: ip as-path access-list 1 permit ^111$.

This configuration creates an access-list named "1" that permits only AS paths that consist of only AS 111. The "^" character matches the beginning of the AS path, the "$" character matches the end of the AS path, and the digits "111" match the AS number. Any other AS path, including those that pass through AS 111, will not match this access-list.

Correct Answer: C

aaa new-model aaa authentication login default group radius ! aaa group server radius RAD server name SERV_RADIUS ! radius server SERV_RADIUS address ipv4 key !

Correct Answer: D

Issuing the following commands will cause RTR2 to advertise the CIDR block 192.168.0.0/16 to the other routers by using BGP:

RTR2(config)# router bgp 65100

RTR2(config-router)# neighbor 172.16.1.2 remote-as 65101

RTR2(config-router)# neighbor 192.168.3.2 remote-as 65100

RTR2(config-router)# network 192.168.0.0 mask 255.255.0.0

RTR2(config-router)# ip route 192.168.0.0 255.255.0.0 null 0 The network command specifies the address that will be inserted into the BGP table. Without the mask keyword, the classful network will be assumed. Because 255.255.0.0, or /16,

is not the natural mask for any Class C address, the mask keyword must also be specified. Thus, 192.168.0.0 and 255.255.0.0 identify the desired address and mask of the 192.168.0.0/16 network prefix.

The router checks the IP forwarding table for an exact match before it advertises the route. Without a matching entry in the IP forwarding table, that route will not be advertised. RTR2 must be able to advertise a CIDR block and not the

individual subnets. A static route is required because BGP requires that a match of the network prefix be present in the forwarding table when using the network command with the mask keyword. Therefore, to ensure an exact match for the

identified prefix exists in the IP forwarding table, and to ensure that the prefix will always be advertised, a static route for 192.168.0.0/16 to null 0 is also required.

The syntax for the network command is shown below:

network network-number [ mask network-mask ] [ route-map map-tag ]

The parameters are:

mask - This parameter is optional and identifies the network or subnetwork to advertise. route-map - This parameter is optional and identifies a preconfigured route-map that will be used to filter specific addresses from being advertised.

The following command set is missing the mask keyword in the network command and the command to create a static route to null 0. The address used in the network command is also incorrect. It should 192.168.0.0:

router bgp 65100

neighbor 172.16.1.2 remote-as 65100

neighbor 192.168.3.2 remote-as 65100

network 192.168.3.0

The following command set is missing the mask keyword in the network command and the command to create a static route to null 0:

router bgp 65100

neighbor 172.16.1.2 remote-as 65101

neighbor 192.168.3.2 remote-as 65100

network 192.168.0.0

The following command set uses an incorrect mask (255.0.0.0) in the command that creates the static route to null 0. It should be 255.255.0.0:

router bgp 65100

neighbor 172.16.1.2 remote-as 65100

neighbor 192.168.3.2 remote-as 65100

network 192.168.0.0 mask 255.255.0.0

ip route 192.0.0.0 255.0.0.0 null 0

Objective:

Layer 3 Technologies

Sub-Objective:

Describe, configure, and verify BGP peer relationships and authentication

References:

Internetworking Case Studies > Using the Border Gateway Protocol for Interdomain Routing > Controlling the Flow of BGP Updates > CIDR and Aggregate Addresses > Aggregation and Static Routes

Correct Answer: A

The following command set would NOT be used because it only applies the access list route-map change_parameters inbound instead of outbound, as would be required:

The ACL 1 allows the 192.168.58.0/24 and the 192.168.127.0/24 subnets, while the ACL 2 allows the 172.161.94.0/24 subnet. The neighbor route-map command specifies a route-map named change_parameters for the 201.60.3.1 BGP

peer. The out keyword at the end of the command indicates that the route-map is applied only to the updates sent by rtrB, and not received by rtrB.

In the following command, the route map change_parameters is defined with the permit keyword. The permit keyword indicates that if a match occurs, the actions specified in the set sub-command are executed:

route-map change_parameters permit 10

match ip-address 2

set metric 500

In this case, this command checks if the IP address of the subnets advertised to rtrA is in the 172.161.94.0/24 subnet (specified by ACL 2). If the IP address matches, then the metric of those routes are set to 500.

In the following command, the route map change_parameters is defined with the permit keyword:

route-map change_parameters permit 20

match ip-address 1

set metric 300

In this case, this command checks if the IP address of the subnets advertised to rtrA is in the 192.168.58.0/24 or the 192.168.127.0/24 subnets (specified by ACL 1) If the IP address matches, then the metric of those routes are set to 300.

Objective:

Layer 3 Technologies

Sub-Objective:

Configure and verify eBGP (IPv4 and IPv6 address families)

References:

Cisco > Home > Support > Technology Support > IP > IP Routing > Design > Design Technotes > BGP Case Studies > Route Maps

Cisco > Cisco IOS IP Routing: Protocol-Independent Command Reference > route-map

Correct Answer: A

Using the service dhcp command at global configuration mode will enable the DHCP and relay services on a Cisco router. By default, these services are already enabled on the router, but they can be disabled using the no service dhcp command. Before the DHCP service can actually function, a pool of addresses must be created and any statically defined addresses (such as the router itself) must be excluded. If the router has two interfaces and needs to issue addresses on both interfaces two pools and two exclusion statements must be present.

Below is an example of a complete configuration taken from a partial output of the show run command. This router has two interfaces 10.0.0.1/24 and 192.168.5.1/24, creating the need for two pools and two exclusion statements. It excludes the address ranges 10.0.0.1-10.0.0.5 from the 10.0.0.0/24 pool and excludes 192.168.5.1-192.168.5.5 from the 192.168.5.0/24 pool, and creates a pool for 10.0.0./24 and 192.168.5.0/24.

The commands RouterA(config)# dhcp enable and RouterA(config)# enable dhcp are incorrect because the syntax is incorrect.

The command RouterA(config-if)# dhcp enable is incorrect because the syntax is incorrect and because it is executed in interface configuration mode. Enabling DHCP is done at the global prompt.

The command RouterA(config-if)# service dhcp is incorrect because it is executed in interface configuration mode. Enabling DHCP is done at the global prompt Objective:

Layer 3 Technologies

Sub-Objective:

Identify, configure, and verify IPv4 addressing and subnetting

References:

Cisco > IP Addressing: DHCP Configuration Guide, Release 15MandT > DHCP Overview Cisco > Cisco IOS IP Addressing Services Command Reference > service dhcp

Correct Answer: D

The routes that will be present in Router R1 are 192.168.5.0 and 10.0.0.0. According to the output, only the route from EIGRP 55 will be redistributed to EIGRP 200. Therefore, the 10.0.0.0 network will be advertised to Router R1 from Router

R2 and the 192.168.5.0 network, which is present in the routing table of Router R2, will be advertised to Router R1.

The 192.168.5.0 network alone would not be correct. The 10.0.0.0 network will be present as well.

The 172.50.0.0 network will not be present because Router 2 is not configured with a redistribution statement for that network. The required statement would be redistribute ospf 1.

Objective:

Layer 3 Technologies

Sub-Objective:

Configure and verify redistribution between any routing protocols or routing sources

References:

Cisco > Home > Support > Technology Support > IP > IP Version 6 > Configure > Configuration Examples and Technotes > Redistributing Routing Protocols

Correct Answer: C

The Forwarding Information Base (FIB) table is created when Cisco Express Forwarding (CEF) is enabled on the router. FIB is a mapping of destination networks and IP addresses to next-hop IP addresses and exit interfaces.

In the scenario, multicast routing has NOT enabled in the router. If it were enabled, the next hop for the 224.0.0.0/4 network would not be listed as drop. A drop means any packets sent to multicast IP addresses will be dropped. If multicast

routing were enabled, the entry for 224.0.0.0 would appear as follows:

Prefix Next Hop Interface

224.0.0.0/4 0.0.0.0

The next hop of 0.0.0.0 means that this traffic will be process switched, and CEF cannot forward the packets.

The table displayed in the scenario contains the default entries in the FIB. These entries will change based on further configuration of the router interfaces and the addition of routes to the routing table through either static routing or through

routing protocols.

No IP addresses have been configured on the router. Had they been configured, the addresses of the networks to which they were connected would be in the table. For example, if the IP address of the FastEthernet 0/1 interface were set to 192.168.1.1/24, three entries would have been added to the table as follows:

While the first IP address represents the directly attached network of which the interface is a member, the second IP address represents the network ID of the network, the third IP address represents the specific IP address assigned to the

interface, and the last IP address represents the broadcast address of the network.

The gateway of last resort has not been set on the router. If it were set, it would be listed along with an IP address for the next hop and the exit interface. An entry for a gateway of last resort (or default route) would resemble the following:

Prefix Next Hop Interface

0.0.0.0/0 192.168.5.5 FastEthernet 0/0

Objective:

Network Principles

Sub-Objective:

Identify Cisco Express Forwarding concepts

References:

Cisco IOS Switching Services Configuration Guide, Release 12.2 > Cisco Express Forwarding Overview Cisco > Home > Support > Product Support > Routers > Cisco 12000 Series Routers > Troubleshoot and Alerts > Troubleshooting

Technotes > Understanding Cisco Express Forwarding (CEF) https://www.ccexpert.us/traffic-share/fib-entries.html

Correct Answer: