Module 6 - NAT for IPv4

Which two statements accurately describe an advantage or a disadvantage when deploying NAT for IPv4 in a network? (Choose two.)

• • NAT adds authentication capability to IPv4.

• • NAT introduces problems for some applications that require end-to-end connectivity.

• • NAT provides a solution to slow down the IPv4 address depletion.

• • NAT causes routing tables to include more information.

• • NAT improves packet handling.

A network administrator wants to examine the active NAT translations on a border router. Which command would perform the task?

• • Router# clear ip nat translations

• • Router# show ip nat translations

• • Router# debug ip nat translations

• • Router# show ip nat statistics

What are two tasks to perform when configuring static NAT? (Choose two.)

• • Configure a NAT pool.

• • Identify the participating interfaces as inside or outside interfaces.

• • Define the outside global address.

• • Define the inside global address on the server

• • Create a mapping between the inside local and inside global addresses.

What is a disadvantage of NAT?

• • The router does not need to alter the checksum of the IPv4 packets.

• • There is no end-to-end addressing.

• • The costs of readdressing hosts can be significant for a publicly addressed network.

• • The internal hosts have to use a single public IPv4 address for external communication.

What is one advantage of using NAT at the edge of the network?

• • Changing ISPs is simpler because the devices on the inside network do not have to be configured with new addresses when the outside address changes.

• • Dynamic NAT allows devices from outside the local network to easily initiate TCP connections to inside hosts.

• • NAT enables end-to-end IPv4 traceability, making troubleshooting easier.

• • Performance is significantly increased because the router does not have to perform as many route lookups.

What benefit does NAT64 provide?

• • It allows sites to use private IPv6 addresses and translates them to global IPv6 addresses.

• • It allows sites to use private IPv4 addresses, and thus hides the internal addressing structure from hosts on public IPv4 networks.

• • It allows sites to connect multiple IPv4 hosts to the Internet via the use of a single public IPv4 address.

• • It allows sites to connect IPv6 hosts to an IPv4 network by translating the IPv6 addresses to IPv4 addresses.

What address translation is performed by static NAT?

• • An inside local address is translated to a specified outside local address.

• • An inside local address is translated to a specified inside global address.

• • An inside local address is translated to a specified outside global address.

• • An outside local address is translated to a specified outside global address.

Using NAT terminology, what is the address of the source host on a private network as seen from inside the network?

• • inside local

• • outside global

• • outside local

• • inside global

Which statement accurately describes dynamic NAT?

• • It always maps a private IP address to a public IP address.

• • It provides an automated mapping of inside local to inside global IP addresses.

• • It dynamically provides IP addressing to internal hosts.

• • It provides a mapping of internal host names to IP addresses.

Why is NAT not needed in IPv6?​

• • The end-to-end connectivity problems that are caused by NAT are solved because the number of routes increases with the number of nodes that are connected to the Internet.

• • Because IPv6 has integrated security, there is no need to hide the IPv6 addresses of internal networks.

• • The problems that are induced by NAT applications are solved because the IPv6 header improves packet handling by intermediate routers.

• • Any host or user can get a public IPv6 network address because the number of available IPv6 addresses is extremely large.