Memory Used for State Tables

If you are manually tweaking the configuration or want to know how much memory to have available in your firewall system, it would be useful to know how much memory each connection takes. The memory requirements for various types of connections are outlined in Table E.1.

Assuming the worst-case scenario (NAT), you would need to allocate at least 57.7MB to handle 100,000 connections.

Table E.1. Approximate memory requirements for specific connections

Connection Type

Memory Requirement

Simple (e.g., accept, no NAT)

325 bytes

NAT (e.g., a standard connection with NAT)

542 bytes

Resources (authentication, content security, and so on)

401 bytes

Encrypted connections

399 bytes

General overhead (not per-connection)