Cisco ASA 5540 User Manual

1-33
Cisco ASA Series CLI Configuration Guide
Chapter 1 Information About NAT
Where to Go Next
Figure 1-26 shows an FTP server and DNS server on the outside. The ASA has a static translation for
the outside server. In this case, when an inside user performs a reverse DNS lookup for 10.1.2.56, the
ASA modifies the reverse DNS query with the real address, and the DNS server responds with the server
name, ftp.cisco.com.
Figure 1-26 PTR Modification, DNS Server on Host Network
Where to Go Next
To configure network object NAT, see Chapter 33, “Configuring Network Object NAT.”
To configure twice NAT, see Chapter 34, “Configuring Twice NAT.”
ftp.cisco.com
209.165.201.10
DNS Server
Outside
Inside
User
10.1.2.27
Static Translation on Inside to:
10.1.2.56
1
2
4
3
Reverse DNS Query
209.165.201.10
Reverse DNS Query Modification
209.165.201.1010.1.2.56
PTR Record
ftp.cisco.com
Security
Device
Reverse DNS Query
10.1.2.56?
304002

Cisco ASA 5540 Specifications

General

Firewall Throughput	650 Mbps
Maximum Firewall Connections	400, 000
VPN Throughput	225 Mbps
Maximum VPN Peers	5, 000
High Availability	Active/Active, Active/Standby
IPSec VPN Throughput	225 Mbps
Memory	1 GB
IPS Throughput	225 Mbps
Security Contexts	50
Flash Memory	64 MB
Form Factor	1U
Power Supply	Dual
Interfaces	4 x 10/100/1000 Ethernet