| 9.5 |  | Port Address Translation (PAT) |
| 9.5.4 |  | Backing up PAT addresses by using multiple PATs |

| PAT theoretically allows for a single IP address to be used by up to 64,000 inside hosts. However, the practical limit is closer to 4000 hosts. While this is easily a sufficient number of hosts to support the needs of most networks, there may be instances were more than 4000 hosts need to be supported. In these instances the PIX Security Appliance allows for backup PAT addresses by configuring multiple globals with the same nat_id.

In Figure , address 192.168.0.9 will be used for all outbound connections from network 10.0.1.0 when the port pool from 192.168.0.8 is at maximum capacity.