SY0-401 question 32 discussion


Which of the following network design elements allows for many internal devices to share
one public IP address?

  • A. DNAT
  • B. PAT
  • C. DNS
  • D. DMZ
Created 10 months, 3 weeks ago by towilliamsjr


Why not just plain old "NAT"?


Because the key to this question is One public IP address and PAT serves to do that.


NAT (Network Address Translation) uses a pool of public addresses that are mapped one-to-one to the private addresses, keeping the port number intact. PAT (Port Address Translation) uses a single outside public address and maps multiple inside addresses to it using different port numbers.


Within NAT, you have Static NAT (one to one) and Dynamic NAT (many to one)


I originally thought it was NAT too, but PAT and NAT are very close in relation.


I guess there is a mistake in this explanation. The part that says "the router assigns it the same local IP address", about the Computer Z... for me, I've learned the router assigns each local devices a different IP address, but the PAT resource also assigns a DIFFERENT port number. (Actually, PAT already uses the real port number conteinad within the device UDP/TCP connection. But this is not necessary for now, for this explanation.)