Re: [FW-1] Anti Spoofing

[Matthias Leu <mleu@FW1-NOSPAMAERASEC.DE>]

"©¿©¬ JGuevarra" wrote:

> Hi To All!
> Why does my mail server cant receive any emails if I
> turned spoofing on both internal and external
> interfaces? It works only if spoofing is none. I want
> to enable spoofing and can received mails at the same
> time.

Hi,
it seems that you use destination static NAT. If so, and you are not
using NG with automatic NAT, the NAT will occur at the internal NIC of
your firewall.
So you have defined in Anti-Spoofing:
  external NIC: OTHER
  internal NIC: This Net
Due to NAT at the internal NIC, you have spoofing at this NIC, because
the official IP of your mail server comes to the internal NIC as
destination. Here the outgoing Anti-Spoofing check is done.
To receive mail, you will have to add this IP to the addresses accepted
by the internal NIC.
Define a workstation with this IP and a group (e.g. intaddresses) with
your internal networks and this new workstation.
  external NIC: OTHER
  internal NIC: SPECIFIC - intaddresses (internal addresses + official
IP of mailserver)
For a better control in the properties for Anti-Spoofing check LOG. If a
spoofing is detected, you will find a drop due to rule 0 in your log.
Hope it helps,
best regards,
Matthias
http://www.fw-1.de
---
AERAsec Network Services and Security GmbH
Wagenberger Strasse 1
D-85662 Hohenbrunn, Germany
http://www.aerasec.de

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