300-101 Exam - Implementing Cisco IP Routing

Answer: A,B 

Explanation: 

To clear one or more entries in the IP routing table, use the following commands in any mode:

Command Purpose

clear ip route {* |

Clears one or more routes from both the

{route |

unicast RIB and all the module FIBs. The

prefix/length}[next-hop route options are as follows:

interface]}

· *--All routes.

[vrf vrf-name]

Example:

· route--An individual IP route.

switch(config)# clear ip

· prefix/length--Any IP prefix.

route

10.2.2.2 · next-hop--The next-hop address · interface--The interface to reach the next-hop address.

The vrf-name can be any case-sensitive, al-phanumeric string up to 32 characters.

Reference:

http://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus5000/sw/unicast/5_0_3_N1_1/Ci

sco_n5k_layer3_ucast_cfg_rel_503_N1_1/l3_manage-routes.html

Answer: B 

Explanation: 

A new interface configuration command, dialer persistent, allows a dial-on-demand routing (DDR) dialer

profile connection to be brought up without being triggered by interesting traffic. When configured, the dialer persistent command starts a timer when the dialer interface starts up and starts the connection when the timer expires. If interesting traffic arrives before the timer expires, the connection is still brought up and set as persistent. The command provides a default timer interval, or you can set a custom timer interval. To configure a dialer interface as persistent, use the following commands beginning in global configuration mode:

Command Purpose

Step 1 Router(config)# interface dialer Creates a dialer interface and number enters interface

Configuration mode.

Step 2 Router(config-if)# ip address Specifies the IP address and mask address mask of the dialer

interface as a node in the destination network to be called.

Step 3 Router(config-if)# encapsulation Specifies the encapsulation type.

type

Step 4 Router(config-if)# dialer string Specifies the remote destination to dial-string class class-name call

and the map class that defines characteristics for calls to this destination.

Step 5 Router(config-if)# dialer pool Specifies the dialing pool to use number for calls to this destination.

Step 6 Router(config-if)# dialer-group Assigns the dialer interface to a group-number dialer group.

Step 7 Router(config-if)# dialer-list Specifies an access list by list dialer-group protocol protocol- number or

by protocol and list name {permit | deny | list number to define the interesting access-list-number} packets that can trigger a call. Step 8 Router(config-if)# dialer

(Optional) Specifies the remote-name user-name

authentication name of the remote router on the destination subnetwork for a dialer interface.

Step 9 Router(config-if)# dialer Forces a dialer interface to be persistent [delay [initial] connected at all

times, even in seconds | max-attempts the absence of interesting traffic.

number]

Reference:

http://www.cisco.com/c/en/us/td/docs/ios/dial/configuration/guide/12_4t/dia_12_4t_book/dia_dia

ler_persist.html

Answer: D 

Explanation: 

Configuring NAT to Allow Internal Users to Access the Internet Using Overloading NAT Router

interface ethernet 0

ip address 10.10.10.1 255.255.255.0

ip nat inside

!--- Defines Ethernet 0 with an IP address and as a NAT inside interface.

interface ethernet 1

ip address 10.10.20.1 255.255.255.0

ip nat inside

!--- Defines Ethernet 1 with an IP address and as a NAT inside interface.

interface serial 0

ip address 172.16.10.64 255.255.255.0

ip nat outside

!--- Defines serial 0 with an IP address and as a NAT outside interface.

ip nat pool ovrld 172.16.10.1 172.16.10.1 prefix 24 !

!--- Defines a NAT pool named ovrld with a range of a single IP

!--- address, 172.16.10.1.

ip nat inside source list 7 pool ovrld overload

!

!

!

!

!--- Indicates that any packets received on the inside interface that

!--- are permitted by access-list 7 has the source

address

!--- translated to an address out of the NAT pool named ovrld.

!--- Translations are overloaded, which allows multiple inside

!--- devices to be translated to the same valid IP

address.

access-list 7 permit 10.10.10.0 0.0.0.31

access-list 7 permit 10.10.20.0 0.0.0.31

!--- Access-list 7 permits packets with source addresses ranging from

!--- 10.10.10.0 through 10.10.10.31 and 10.10.20.0

through 10.10.20.31.

Note in the previous second configuration, the NAT pool "ovrld"only has a range of one address. The

keyword overload used in the ip nat inside source list 7 pool

ovrld overload command allows NAT to translate multiple inside devices to the single address in the pool.

Reference:

http://www.cisco.com/en/US/tech/tk648/tk361/technologies_tech_note09186a0080094e77.shtml

Answer: A 

Explanation: 

Answer: B 

Explanation: 

Answer: Here is the solution below: 

Explanation: 

To troubleshoot the problem, first issue the show running-config on all of 4 routers. Pay more attention to the outputs of routers R2 and R3 The output of the "show running-config" command of R2: 

The output of the "show running-config" command of R3: 

We knew that all areas in an Open Shortest Path First (OSPF) autonomous system must be physically connected to the backbone area (Area 0). In some cases, where this is not possible, we can use a virtual link to connect to the backbone through a non-backbone area. The area through which you configure the virtual link is known as a transit area. In this case, the area 11 will become the transit area. Therefore, routers R2 and R3 must be configured with the area <area id> virtual-link <neighbor router-id>command. + Configure virtual link on R2 (from the first output above, we learned that the OSPF process ID of R2 is 1): 

R2>enable 

R2#configure terminal 

R2(config)#ipv6 router ospf 1 

R2(config-rtr)#area 11 virtual-link 3.3.3.3 

Save the configuration: 

R2(config-rtr)#end 

R2#copy running-config startup-config 

(Notice that we have to use neighbor router-id 3.3.3.3, not R2's router-id 2.2.2.2) + Configure virtual link on R3 (from the second output above, we learned that the OSPF process ID of R3 is 1 and we have to disable the wrong configuration of "area 54 virtual-link 4.4.4.4"): 

R3>enable 

R3#configure terminal 

R3(config)#ipv6 router ospf 1 

R3(config-rtr)#no area 54 virtual-link 4.4.4.4 

R3(config-rtr)#area 11 virtual-link 2.2.2.2 

Save the configuration: 

R3(config-rtr)#end 

R3#copy running-config startup-config 

You should check the configuration of R4, too. Make sure to remove the incorrect configuration statements to get the full points. 

R4(config)#ipv6 router ospf 1 

R4(config-router)#no area 54 virtual-link 3.3.3.3 

R4(config-router)#end 

After finishing the configuration doesn’t forget to ping between R1 and R4 to make sure they work. 

Note. If you want to check the routing information, use the show ipv6 route command, not "show ip route". 

Answer: A 

Explanation: 

DMVPN Tunnel Flaps Intermittently Problem DMVPN tunnel flaps intermittently. Solution

When DMVPN tunnels flap, check the neighborship between the routers as issues with neighborship

formation between routers may cause the DMVPN tunnel to flap. In order to resolve this problem, make

sure the neighborship between the routers is always up. Reference: http://www.cisco.com/c/en/us/support/

docs/security-vpn/ipsec-negotiation-ike- protocols/29240-dcmvpn.html#Prblm1

Answer: B 

Explanation: 

Answer: C 

Explanation: 

OSPFv3 uses link-local IPv6 addresses for neighbor discovery and other features, so if any IPv6 traffic

filters are implemented be sure to include the link local address so that it is permitted in the filter list.

Reference: http://www.cisco.com/c/en/us/td/docs/switches/datacenter/sw/5_x/nx- os/unicast/configuration/

guide/l3_cli_nxos/l3_ospfv3.html

Answer: A 

Explanation: