Cisco Firewalls

Chapter 8. Through ASA Using NAT

This chapter covers the following topics:

• The Nat-control Model

• Outbound NAT analysis

• Address publishing for inbound access

• Inbound NAT analysis

• Dual NAT

• Disabling TCP sequence number randomization

• Defining connection limits with NAT rules

“Wheresoever we have spoken plainly, there we have spoken nothing. But where we have used riddles and figures, there we have hidden the truth” —Rosarium Philosophorum

Network Address Translation (NAT) is a widespread technique for creating mappings between internal and external address spaces. The simplest NAT mode of operation establishes a one-to-one correspondence between the real source address and the virtual (or translated) source address. Some other ...