CCNA routing and switching chapter 8 and 9
The ip helper-address command is missing
1. An administrator has configured a DHCPv4 relay router and issued these commands: Router(config)# interface g0/0 Router(config-if)# ip address 10.0.1.1 255.255.255.0 Router(config-if)# no shutdown Router(config-if)# exit Router(config)# ip dhcp pool RELAY Router(dhcp-config)# end The clients are not receiving IP parameters from the DHCPv4 server. What is a possible cause?
R1(config)# ip nat inside source static tcp 192.168.5.25 8080 209.165.200.230 80
1A network administrator is configuring a static NAT on the border router for a web server located in the DMZ network. The web server is configured to listen on TCP port 8080. The web server is paired with the internal IP address of 192.168.5.25 and the external IP address of 209.165.200.230. For easy access by hosts on the Internet, external users do not need to specify the port when visiting the web server. Which command will configure the static NAT?
dynamic NAT
A company designs its network so that the PCs in the internal network are assigned IP addresses from DHCP servers, and the packets that are sent to the Internet are translated through a NAT-enabled router. What type of NAT enables the router to populate the translation table from a pool of unique public addresses, as the PCs send packets through the router to the Internet?
DHCPv6 INFORMATION-REQUEST
A company implements the stateless DHCPv6 method for configuring IPv6 addresses on employee workstations. After a workstation receives messages from multiple DHCPv6 servers to indicate their availability for DHCPv6 service, which message does it send to a server for configuration information?
FF-FF-FF-FF-FF-FF and 255.255.255.255
A company uses DHCP servers to dynamically assign IPv4 addresses to employee workstations. The address lease duration is set as 5 days. An employee returns to the office after an absence of one week. When the employee boots the workstation, it sends a message to obtain an IP address. Which Layer 2 and Layer 3 destination addresses will the message contain?
It should use the information that is contained in the RA message and contact a DHCPv6 server for additional information.
A network administrator configures a router to send RA messages with M flag as 0 and O flag as 1. Which statement describes the effect of this configuration when a PC tries to configure its IPv6 address?
a NAT pool named corp that defines the starting and ending public IP addresses
A network administrator configures the border router with the command R1(config)# ip nat inside source list 4 pool corp. What is required to be configured in order for this particular command to be functional?
an access list that is numbered 4 that defines the private addresses that are affected by NAT
A network administrator configures the border router with the command R1(config)# ip nat inside source list 4 pool corp. Which ACL is required to be configured in order for this command to function?
Router# show ip nat translations
A network administrator wants to examine the active NAT translations on a border router. Which command would perform the task?
The company has more private IP addresses than available public IP addresses.
A network engineer has configured a router with the command ip nat inside source list 4 pool corp overload. Why did the engineer use the overload option?
a many-to-one address mapping between local and global addresses
A technician is required to configure an edge router to use a different TCP port number for each session with a server on the Internet. What type of Network Address Translation (NAT) should be implemented?
The client should automatically configure an IPv6 address and then contact a DHCPv6 server for more information.
After booting, a client receives an ICMPv6 RA message with the M flag set to 0 and the O flag set to 1. What does this indicate?
configuring the router to obtain IP parameters from a DHCPv4 server
An administrator issues the commands: Router(config)# interface g0/1 Router(config-if)# ip address dhcp What is the administrator trying to achieve?
stateless DHCPv6
An administrator wants to configure hosts to automatically assign IPv6 addresses to themselves by the use of Router Advertisement messages, but also to obtain the DNS server address from a DHCPv6 server. Which address assignment method should be configured?
the pool of global address
What is defined by the ip nat pool command when configuring dynamic NAT?
DHCPREQUEST
As a DHCPv4 client lease is about to expire, what is the message that the client sends the DHCP server?
255.255.255.255
What is the destinatioin IP address when an IPv4 host sends a DHCPDISCOVER message?
excluded-address 10.0.15.1 10.0.15.15
Fill in the blank. Do not abbreviate. Type a command to exclude the first fifteen useable IP addresses from a DHCPv4 address pool of the network 10.0.15.0/24. Router(config)# ip dhcp ___________________________________
server events
Fill in the blank. Do not abbreviate.An administrator is troubleshooting a DHCPv4 issue on a router. By issuing the debug ip dhcp _________________________ command, the administrator can watch, in real time, the IP address assignments that are performed by the router.
Port Address Translation
Fill in the blank. Do not use abbreviations. NAT overload is also known as ________________________________.
It allows many internal hosts to share the same public IPv4 address.
What is the major benefit of using NAT with Port Address Translation?
It sends an ICMPv6 Neighbor Solicitation message with the IPv6 address as the target IPv6 address
How does an IPv6 client ensure that it has a unique address after it configures its IPv6 address using the SLAAC allocation method?
SLAAC
In which alternative to DHCPv6 does a router dynamically provide IPv6 configuration information to hosts?
Step 1 -> DHCPDISCOVER Step 2 -> DHCPOFFER Step 3 -> DHCPREQUEST Step 4 -> DHCPACK
Match the DHCP message types to the order of the DHCPv4 process. (Not all options are used.)
- step 5 => R1 replaces the address 192.168.10.10 with a translated inside global address. - step 2 => R1 checks the NAT configuration to determine if this packet should be translated. - step 4 => R1 selects an available global address from the dynamic address pool. - step 1 => The cost sends packets that request a connection to the server at the address 209.165.200.254 - step 3 => If there is no translation entry for this IP address, R1 determines that the source address 192.168.10.10 must be translated.
Match the steps with the actions that are involved when an internal host with IP address 192.168.10.10 attempts to send a packet to an external server at the IP address 209.165.200.254 across a router R1 that is running dynamic NAT. (Not all options are used.)
Step 1 - Exclude IP addresses Step 2 - Configure a DHCP pool Step 3 - Define the default gateway router
Order the steps of configuring a router as a DHCPv4 server. (Not all options are used.)
Not enough information is given to determine if both static and dynamic NAT are working.
Refer to the exhibit. The NAT configuration applied to the router is as follows: ERtr(config)# access-list 1 permit 10.0.0.0 0.255.255.255ERtr(config)# ip nat pool corp 209.165.201.6 209.165.201.30 netmask 255.255.255.224ERtr(config)# ip nat inside source list 1 pool corp overloadERtr(config)# ip nat inside source static 10.10.10.55 209.165.201.4ERtr(config)# interface gigabitethernet 0/0ERtr(config-if)# ip nat insideERtr(config-if)# interface serial 0/0/0ERtr(config-if)# ip nat outside Based on the configuration and the output shown, what can be determined about the NAT status within the organization?
The router is configured for stateless DHCPv6 operation
Refer to the exhibit. A network administrator is configuring a router for DHCPv6 operation. Which conclusion can be drawn based on the commands?
The router is configured for stateless DHCPv6 operation
Refer to the exhibit. A network administrator is implementing stateful DHCPv6 operation for the company. However, the clients are not using the prefix and prefix-length information that is configured in the DHCP pool. The administrator issues a show ipv6 interface command. What could be the cause of the problem?
Interface S0/0/0 should be identified as the outside NAT interface.
Refer to the exhibit. A technician is configuring R2 for static NAT to allow the client to access the web server. What is a possible reason that the client PC cannot access the web server?
- the M flag is set to 1 in RA messages - used the address command to create a pool of addresses for clients - enabled on the client with the ipv6 address dhcp command
Stateful DHCPv6 Traits
-enabled in RA messages with the ipv6 nd other-config-flag command - clients send only DHCPv6 INFORMATION-REQUEST messages to the server - enabled on the client with the ipv6 address autoconfig command
Stateless DHCPv6 Traits
router
Typically, which network device would be used to perform NAT for a corporate environment?
The router is intended to be used as a SOHO gateway. This is an ISP requirement.
Under which two circumstances would a router usually be configured as a DHCPv4 client? (Choose two.)
It saves public IP addresses. It adds a degree of privacy and security to a network.
What are two benefits of NAT? (Choose two.)
Define a pool of global addresses to be used for overload translation. Identify the inside interface.
What are two of the required steps to configure PAT? (Choose two.)
They allow sites to be combined without creating any address conflicts.
What is a characteristic of unique local addresses?
There is no end-to-end addressing.
What is a disadvantage of NAT?
It can provide relay services for multiple UDP services.
What is an advantage of configuring a Cisco router as a relay agent?
provides flexibility in designing the IPv4 addressing scheme
What is an advantage of deploying IPv4 NAT technology for internal hosts in an organization?
It is a temporary mechanism to assist in the migration from IPv4 to IPv6.
What is correct in relation to NAT for IPv6?
It is a SOHO or home broadband router
What is the most likely scenario in which the WAN interface of a router would be configured as a DHCP client to be assigned a dynamic IP address from an ISP?
conserve IPv4 addresses
What is the primary purpose of NAT?
It binds the inside local address and local port to the specified inside global address and global port.
What is the purpose of entering the command ip nat inside source static tcp 192.168.10.2 80 209.165.200.223 8080 at the global configuration prompt?
Port forwarding allows an external user to reach a service on a private IPv4 address that is located inside a LAN.
What is the purpose of port forwarding?
The Cisco router will exclude 15 IP addresses from being leased to DHCP clients.
What is the result of a network technician issuing the command ip dhcp excluded-address 10.0.15.1 10.0.15.15 on a Cisco router?
the MAC address of the IPv6 enabled interface
What is used in the EUI-64 process to create an IPv6 interface ID on an IPv6 enabled interface?
DAD
What process is used in ICMPv6 for a host to verify that an IPv6 address is unique before configuring it on an interface?
The router is configured for SLAAC operation.
Refer to the exhibit. A network administrator is implementing the stateless DHCPv6 operation for the company. Clients are configuring IPv6 addresses as expected. However, the clients are not getting the DNS server address and the domain name information configured in the DHCP pool. What could be the cause of the problem?
stateless DHCPv6
Refer to the exhibit. Based on the output that is shown, what kind of IPv6 addressing is being configured?
PAT using an external interface
Refer to the exhibit. Based on the output that is shown, what type of NAT has been implemented?
The ipv6 dhcp relay command should be applied to interface Gig0/0.
Refer to the exhibit. PC-A is unable to receive an IPv6 address from the stateful DHCPv6 server. What is the problem?
Access-list 1 is misconfigured.
Refer to the exhibit. Router R1 is configured for PAT. What is a possible reason that the addresses in the network are not translated?
The router NAT configuration has an incorrect inside local address.
Refer to the exhibit. Router R1 is configured with static NAT. Addressing on the router and the web server are correctly configured, but there is no connectivity between the web server and users on the Internet. What is a possible reason for this lack of connectivity?
- Step 1 —> The client uses the inside global address of the web server as the destination address to send a packet to the web server. - Step 2 —> R2 receives the packet on its outside interface, then checks and locates the destination address in its NAT table. - Step 3 —> R2 replaces the inside global address with the inside local address of the web server and forwards the packet to the web server. - Step 4 —> The web server uses the outside global address of the client as the destination address when responding. - Step 5 —> R2 receives the packet from the web server. R2 checks the NAT table, then translates the source address of the web server into an inside global address and forwards the packet.
Refer to the exhibit. Router R2 is configured with static NAT. Place in order the steps that occur when the client accesses the web server through the router. (Not all options are used.)
defines which addresses can be translated
Refer to the exhibit. What is the purpose of the command marked with an arrow shown in the partial configuration output of a Cisco broadband router?
Add the ipv6 dhcp relay command to interface Fa0/0.
Refer to the exhibit. What should be done to allow PC-A to receive an IPv6 address from the DHCPv6 server?
209.165.20.25
Refer to the exhibit. Which address or addresses represent the inside global address?
EUI-64 random generation
What two methods can be used to generate an interface ID by an IPv6 host that is using SLAAC? (Choose two.)
The client may have received offers from multiple servers, and the broadcast serves to implicitly decline those other offers.
When a client is requesting an initial address lease from a DHCP server, why is the DHCPREQUEST message sent as a broadcast?
The request to the server for the seventh user fails.
When dynamic NAT without overloading is being used, what happens if seven users attempt to access a public server on the Internet when only six addresses are available in the NAT pool?
broadcast DHCPREQUEST
Which DHCPv4 message will a client send to accept an IPv4 address that is offered by a DHCP server?
client hardware address
Which address does a DHCPv4 server target when sending a DHCPOFFER message to a client that makes an address request?
· ipv6 address dhcp
Which command should be configured on a router interface to set the router as a stateful DHCPv6 client?
Router# show ip dhcp binding
Which command will allow a network administrator to check the IP address that is assigned to a particular MAC address?
ff02::1:2
Which destination IP address is used when an IPv6 host sends a DHCPv6 SOLICIT message to locate a DHCPv6 server?
dynamic allocation
Which is a DHCPv4 address allocation method that assigns IPv4 addresses for a limited lease period?
· DHCPREQUEST
Which message does an IPv4 host use to reply when it receives a DHCPOFFER message from a DHCP server?
It uses the destination TCP or UDP port number on the incoming packet.
Which method is used by a PAT-enabled router to send incoming packets to the correct inside hosts?
It provides an automated mapping of inside local to inside global IP addresses.
Which statement accurately describes dynamic NAT?
They are not routable across the Internet.
Which statement describes IPv6 ULAs?
the link-local address of the router interface that is attached to the network
A company uses the SLAAC method to configure IPv6 addresses for the employee workstations. Which address will a client use as its default gateway?