Section 22 - Enabling Internet Connectivity

Question 1

NAT

Answer 1

NETWORK ADDRESS TRANSLATION

Mechanism that is used to translate private addresses into public addresses.

Question 2

Where is NAT usually implemented?

Answer 2

Border Devices such as FWs or Routers

Question 3

Command to verify DHCP-specific information

Answer 3

show dhcp lease

show dhcp server

Question 4

Different flavors of NAT and Describe

Answer 4

1. Static NAT: 1 to 1 address mapping
2. Dynamic NAT: Many to many address mapping
3. PAT: Many to one address mapping

Question 5

Different Classifications of NAT and Describe

Answer 5

Inside Addresses - addresses that belong on network
Outside Addresses - address that do not belong on network.

Local Address - addresses that are ‘seen’ by a local device.
Global Addresses - Public addresses that are seen publicly.

Question 6

Benefits of NAT

Answer 6

1. Conserves Public addresses
2. Increases flexibility of connections to public networks.
3. Provides consistency for internal network addressing schemes.
4. Can translate all private addresses to only one public address.

Question 7

Disadvantages of NAT

Answer 7

1. End-to-end functionality is lost.
2. Traceability is lost.
3. Difficult to tunnel
4. TCP can be disrupted.
5. Can degrade Network performance.

Question 8

Which flavor of NAT is a home router and why?

Answer 8

PAT -

Because the ISP assigns one IP to the router, and then the routers assigns multiple private IPs.

Question 9

Which flavors of NAT have a time-out protocol?

Answer 9

PAT and Dynamic NAT

Question 10

When only inside PAT is performed, what is translated?

Answer 10

Source IPv4 and Source Port Numbers of outbound Packets.

Destination IPv4 and port numbers of inbound packets

Question 11

Which flavor of NAT enables one public address to be used for multiple internal private hosts?

Answer 11

PAT