2-11: NAT Flashcards
What is a disadvantage of NAT?
There is no end-to-end addressing.
If a host with an internal IP of 192.168.10.10 attempts to send a packet to an external server at the IP 209.165.200.254 across a router running dynamic NAT, what is the second step in resolving the address?
Router checks the NAT configuration to determines if this packet should be translated.
The Inside Local address is usually what?
An RFC 1918 address
What has to be done in order to complete the static NAT configuration on R1?
Interface S0/0/0 should be configured with the command ip nat outside.
Private IPs are often referred to as
Non-routeable or RFC1918 addresses
If a host with an internal IP of 192.168.10.10 attempts to send a packet to an external server at the IP 209.165.200.254 across a router running dynamic NAT, what is the third step in resolving the address?
If there is no translation entry for this IP address, the router determines that the internal address must be translated.
Several key servers in an organization must be directly accessible from the Internet. What addressing policy should be implemented for these servers?
Assign static internal addresses and public external addresses to each of the servers.
If a host with an internal IP of 192.168.10.10 attempts to send a packet to an external server at the IP 209.165.200.254 across a router running dynamic NAT, what is the fourth step in resolving the address?
The router selects an available global address from the dynamic address pool.
What will be the effect of entering the command that is shown in the exhibit on R2 as part of the dynamic NAT configuration?
R2(config)# ip nat inside source list 1 pool NAT-POOL1
It will bind NAT-POOL1 with ACL 1.
Which type of NAT maps a single inside local address to a single inside global address?
static
What is the purpose of port forwarding?
Port forwarding allows an external user to reach a service on a private IPv4 address that is located inside a LAN.
Which statement accurately describes dynamic NAT?
It provides an automated mapping of inside local to inside global IP addresses.
What is the purpose of the command marked with an arrow shown in the partial configuration output of a Cisco broadband router?
Defines which addresses can be translated
The Outside Global address is what?
The Reachable IP of a host on the internet.
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?
The company has more private IP addresses than available 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?
A NAT pool named corp that defines the starting and ending public IP addresses
If a host with an internal IP of 192.168.10.10 attempts to send a packet to an external server at the IP 209.165.200.254 across a router running dynamic NAT, what is the first step in resolving the address?
The host sends packets that request a connection to the address.
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?
The request to the server for the seventh user fails.
What is a characteristic of unique local addresses?
They allow sites to be combined without creating any address conflicts.
Based on the configuration and the output shown, what can be determined about the NAT status within the organization?
Not enough information is given to determine if both static and dynamic NAT are working.
Typically, which network device would be used to perform NAT for a corporate environment?
Router
The Inside Global address is what?
The Public IP inside host is given as it exits NAT
What is the group of public IPv4 addresses used on a NAT-enabled router known as?
Inside global addresses
When NAT is employed in a small office, which address type is typically used for hosts on the local LAN?
Private IP addresses
What are two required steps to configure PAT?
Define a pool of global addresses to be used for overload translation. Identify the inside interface.
Which configuration would be appropriate for a small business that has the public IP address of 209.165.200.225/30 assigned to the external interface on the router that connects to the Internet?
access-list 1 permit 10.0.0.0 0.255.255.255 ip nat inside source list 1 interface serial 0/0/0 overload
If a host with an internal IP of 192.168.10.10 attempts to send a packet to an external server at the IP 209.165.200.254 across a router running dynamic NAT, what is the fifth step in resolving the address?
The router replaces the internal address with the translated global address.
R1 is configured for NAT as displayed. What is wrong with the configuration?
NAT-POOL2 is not bound to ACL 1.
Which version of NAT allows many hosts inside a private network to simultaneously use a single inside global address for connecting to the Internet?
PAT
Based on the output that is shown, what type of NAT has been implemented?
PAT using an external interface
