Comment by paulddraper

1. NAT is not firewall.

2. "NAT" is changing addresses. PAT (port address) is the most common type.

3. "Firewall" is dropping packets.

4. The same component can (and often does) do address translation and filtering.

5. A NAT precludes some security features: "NAT reduces the number of options for providing security." [1]

6. A NAT provides some degree of anonymity.

7. IPv6 can have (but does not require) NAT.

[1] https://www.rfc-editor.org/rfc/rfc1631.html