Transparent Nat - THOMSON SpeedTouch Configuration Manual

Transparent NAT

6.3.5 Transparent NAT
Introduction
Transparent Basic NAT
46
A Transparent NAT map is considered as transparent if inside and outside address
are equal. No translation is performed on packet headers. A transparent map is used
in order to avoid issues with NAT unfriendly applications.
There are different transparent maps:
Transparent Basic NAT
Transparent Two-Way NAT
Transparent N-N NAT
For every transparent natmap it is necessary to add:
!
an interface route on the SpeedTouch™ to the LAN device (inside
address).
a proxy ARP on the SpeedTouch™, to reach the default gateway (BAS)
from the LAN device.
Create a new NAT map and fill in the fields.
Portmap Value
properties
ppp_pppoa
Interface
Protocol any
40.0.0.1 (the public IP you have)
Outside address
Access list 40.0.0.1
Transparent Basic NAT is only for outbound sessions. In this case the access list and
the outside address will be the same. For example 40.0.0.1.
Transparent Basic NAT is applicable for protocols with the host address in the
payload. NAT would translate the host address, but not the payload, by which the
packet becomes invalid.
E-NIT-CTC-20040716-0004 v1.0