Allied Telesis AT-iMG634 - R2 User's Guide download pdf (Page 439)

100

101

NAT and secondary IP addresses Network address translation - NAT

4-137

iMG/RG Software Reference Manual (IPNetwork Functions)

However, if the firewall is enabled, there is a matter of precedence to consider if reserved mapping has been

created for a particular TCP port but the firewall is not configured to allow in TCP data for that port.

In this case the blocking by the firewall will take precedence.

So, when the firewall has been enabled, care must be taken to ensure that when NAT reserved mapping are cre-

ated, the firewall is also configured to allow in the traffic for which the reserve mapping is defined.

4.4.3.2 NAT and dynamic port opening

The description of Dynamic Port Opening (see Security section) discussed that feature in the context of the

firewall – i.e. the Dynamic Port Opening feature was presented as being required to allow secondary sessions

in through the firewall.

It should be noted that, by default, incoming sessions are not allowed through by NAT either. So, if NAT is ena-

bled, even if the firewall is not enabled, then if you wish to be able to access services that involve incoming sec-

ondary sessions, then you will need to create Dynamic Port Opening definitions for those services.

So, for example, if you have NAT enabled on the router, and wish for users on the LAN to be able to success-

fully access external RealServers, it will be necessary to create a Dynamic Port Opening definition.

4.4.4 NAT and secondary IP addresses

NAT services work also with secondary IP addresses.

In this case it's necessary create a secondary IP address using IP INTERFACE ADD SECONDARYIPADDRESS

command and then create a security interface based on this secondary IP interface.

Then a global pool must be added and a reserved mapping configured. If using PPPoE encapsulation, secondary

IP addresses in the global pool must be on a separate subnet. If the secondary IP addresses are on the same sub-

net as the external IP address, the addresses are not visible to the external network.

4.4.5 NAT command reference

This section describes the commands available on AT-iMG Models to enable, configure and manage NAT mod-

ule.

4.4.5.1 NAT CLI commands

The table below lists the NAT commands provided by the CLI:

1 2 ... 434 435 436 437 438 439 440 441 442 443 444 ... 997 998

Comments to this Manuals

No comments

Allied Telesis AT-iMG634 - R2 User's Guide Page 439

Comments to this Manuals

Related products and manuals for Gateways/controllers Allied Telesis AT-iMG634 - R2