Cisco ASA 5512-X Cli Configuration Guide

1-31
Cisco ASA Series CLI Configuration Guide
Chapter 1 Information About NAT
DNS and NAT
Figure 1-24 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 requests the address for ftp.cisco.com from the DNS
server, the DNS server responds with the real address, 209.165.20.10. Because you want inside users to
use the mapped address for ftp.cisco.com (10.1.2.56) you need to configure DNS reply modification for
the static translation.
Figure 1-24 DNS Reply Modification, DNS Server on Host Network
Figure 1-24 shows an FTP server and DNS server on the outside IPv4 network. The ASA has a static
translation for the outside server. In this case, when an inside IPv6 user requests the address for
ftp.cisco.com from the DNS server, the DNS server responds with the real address, 209.165.200.225.
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
130022
1
2
7
6
5
4
3
DNS Query
ftp.cisco.com?
DNS Reply
209.165.201.10
DNS Reply Modification
209.165.201.10 10.1.2.56
DNS Reply
10.1.2.56
FTP Request
209.165.201.10
Dest Addr. Translation
209.165.201.1010.1.2.56
FTP Request
10.1.2.56
Security
Appliance

Cisco ASA 5512-X Specifications

General

Firewall Throughput	1.2 Gbps
VPN Throughput	200 Mbps
Maximum VPN Peers	250
Integrated IPS	Yes
IPS Throughput	250 Mbps
RAM	4 GB
Power Supply	AC, 100-240V
Security Contexts	2 (Standard), 50 (with Security Contexts license)
Interfaces	6 x Gigabit Ethernet
Dimensions (H x W x D)	1.75 x 17.5 x 14.5 inches
Weight	16 lbs