How to Interpret NAT Translation Table with PAT and Static

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✗

  The router is configured with static NAT for two internal hosts.

  Why it's wrong here

  Static NAT is configured with a one-to-one inside local-to-inside global binding that never changes and does not inspect or translate Layer 4 ports. The displayed translation entries show the same inside global address being reused for multiple sessions from 10.0.0.20, with each session distinguished by a different source port, which is impossible under static NAT. Static entries would also remain in the table even when idle, whereas these entries appear to be dynamic and port-based.

• ✓

  The router is performing Port Address Translation (PAT) for multiple sessions from the same internal host.

  Why this is correct

  The translation table shows two entries both sourced from inside local 10.0.0.20, and both are assigned the same inside global address 192.0.2.20. The differentiator between the sessions is the source port, which is the defining behavior of Port Address Translation (PAT) / NAT overload. PAT lets one internal host sustain multiple concurrent TCP or UDP flows through a single public IP by rewriting each packet's source port along with the IP address, which matches the entries given in the question.

• ✗

  The router is performing destination NAT.

  Why it's wrong here

  Destination NAT, often called port forwarding or NAT for inbound traffic, changes the destination IP address in packets from an outside global address to an inside local or outside local address. In this output, the outside local and outside global columns are the same for both entries, so no destination rewriting is occurring; the translation is happening on the source side of the sessions. A destination NAT entry would show a different outside local address in the table for those same outside global addresses.

• ✗

  The inside local address 10.0.0.20 is using two different global addresses.

  Why it's wrong here

  The statement claims 10.0.0.20 is being mapped to two different global addresses, but both translation entries use the same inside global IP 192.0.2.20. The reason there are two lines is that PAT creates one translation entry per session, and these two sessions are differentiated solely by their source ports, not by the inside global address. Misreading this as two global addresses is a common trap; the address is identical, only the port is different.