Netopia Netopia ISDN Router, R310 }

IP Setup and Network Address Translation 9-5

In order to support this type of mapping, you deﬁne two address ranges. First, you deﬁne a public range which

contains the ﬁrst and last public address to be used and the way in which these addresses should be used

(PAT, static, or dynamic). You then conﬁgure an address map which deﬁnes the private IP address or addresses

to be used and which public range they should be mapped to. You add the address map to the list of address

maps which are conﬁgured, creating a Map List. The mappings in the Map List are order-dependent and are

compared in order from the top of the list to the bottom. If a particular resource is not available, subordinate

mappings can be deﬁned that will redirect trafﬁc.

Additional Features

■Multiple public addresses, none of which have to be the same as the Connection Proﬁle WAN IP address.

Any public addresses not associated with the Connection Proﬁle WAN IP address must have a static route

pointing to it from a router on the public network if public users are expected to be able to access the

NATed machines or services.

■Default PAT to a DHCP- or PPP-assigned address.

■1:1 Dynamically Assigned NAT Mapping. This allows internal addresses to be temporarily assigned a public

IP address to use for NAT. When the private host is ﬁnished communicating, the public IP address is made

available for use by other internal hosts again.

■1-to-1 static NAT mapping.

An internal private address is permanently mapped to an external address. TCP and UDP port addresses

are not altered.

■Multiple Many-to-1 PAT mappings on a single interface.

PAT addresses may be assigned to speciﬁc private address subnets; not all internal machines need to be

included on a PAT mapping list.

■Coexistent mapped and unmapped trafﬁc on a public interface.

If the router's IP address is not included in a NAT list, it will be invisible to the external network.

■Mapped services (exports) may use multiple public addresses.

■NAT maps per WAN interface, similar to the ﬁlter rules.

Private Addresses IP HostPublic Addresses NAT Type

192.168.1.253

192.168.1.254

206.1.1.1

206.1.1.2

206.1.1.3

206.1.1.4

1:1 Static

206.1.1.5

206.1.1.6

192.168.1.1 – 252

Web/FTP Server

Email Server

1:1 Dynamic

LAN Users

206.1.2.1 – 6 LAN Users

1:Many PAT

(possible later)

192.168.1.1

}

192.168.1.1 – 252