Firewalls and Tunnels
5-22
Hewlett-Packard Company Virtual Private Networking Concepts Guide
One-Way In Firewall Rules
One-Way In Firewall Rules
One-Way In Firewall Rules
One-Way In Firewall Rules
One-way in firewall rules allow devices on a black (untrusted)
network to establish communication sessions with devices on
the red (trusted) network. No network address translation
(NAT) is performed when a session is established through a
stateful one-way in firewall rule. One-way in firewall rules can
grant access to services executing on devices on a red (trusted)
subnet having routed IP addresses.
If you want to allow SMTP mail from people on the Internet to
be sent into the mail server, define a one-way in rule as described
in the following table.
Parameter
Parameter
Parameter
Parameter
Description
Description
Description
Description
Parameter Value
Parameter Value
Parameter Value
Parameter Value
Comments
Comments
Comments
Comments
From IP address
0.0.0.0
The mail can come
from any IP address.
From subnet mask
0.0.0.0
From application
port
ALL
The application port
used to send the
mail is usually
unknown.
To IP address
198.53.144.2
Assumes that the
mail record
associated with
your domain name
points to this
address.
To subnet mask
255.255.255.255
The mail must
arrive at this IP
address only.
To application port
25
The SMTP mail
server listens on
this port.