Cisco 5510 - ASA SSL / IPsec VPN Edition Configuration Guide

27-33
Cisco ASA 5500 Series Configuration Guide using ASDM
OL-20339-01
Chapter 27 Configuring Network Object NAT
Configuration Examples for Network Object NAT
When an inside host sends a DNS request for the address of ftp.cisco.com, the DNS server replies with
the mapped address (209.165.201.10). The adaptive security appliance refers to the static rule for the
inside server and translates the address inside the DNS reply to 10.1.3.14. If you do not enable DNS reply
modification, then the inside host attempts to send traffic to 209.165.201.10 instead of accessing
ftp.cisco.com directly.
Figure 27-63 DNS Reply Modification
Step 1 Create a network object for the FTP server address:
DNS Server
Outside
Inside
User
130021
1
2
3
4
5
DNS Reply Modification
209.165.201.10 10.1.3.14
DNS Reply
209.165.201.10
DNS Reply
10.1.3.14
DNS Query
ftp.cisco.com?
FTP Request
10.1.3.14
Security
Appliance
ftp.cisco.com
10.1.3.14
Static Translation
on Outside to:
209.165.201.10

Cisco 5510 - ASA SSL / IPsec VPN Edition Specifications

General

Brand	Cisco
Model	5510 - ASA SSL / IPsec VPN Edition
Category	Firewall
Language	English