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.
Explanation: When NAT is used, the inside network can be addressed with RFC 1918 private addresses and the outside address is provided by the ISP. When changing to a new ISP, the hosts on the inside network do not have to have their addresses changed. NAT prevents end-to-end IPv4 traceability, making troubleshooting more difficult. Performance can be adversely affected with NAT, as the router needs to change the IP, and possibly TCP/UDP headers on each packet. Dynamic NAT does not allow outside devices to easily initiate connections to inside devices unless an outbound connection has already been made.
Related exam: CCNA 3 v7 Module 6 Quiz - NAT for IPv4
