Netopia R2020 User Reference Manual page 129

Public Addresses
206.1.1.1
206.1.1.2
206.1.1.3
206.1.1.4
206.1.1.5
206.1.1.6
In order to support this type of mapping, the private addresses and public addresses are separated and are
assigned to ranges. Each range consists of a contiguous set of one or more addresses. The router allocates
the addresses in that range based on the type (static or PAT), and other relevant attributes. The range defines
the rules for distributing the exterior addresses. NAT maps, kept in a list similar to a firewall or filter list, contain
the private addresses and the name pointer of the range to use to get a public address. The maps function as
an access control list to the resource contained in the range.
F F F F e e e e a a a a t t t t u u u u r r r r e e e e s s s s
The Netopia R2020 Router features the following:
Default behavior consistent with previous firmware versions, including PAT to a DHCP- or PPP-assigned
address.
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 remapping 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 interface, similar to the filter rules.
S S S S u u u u p p p p p p p p o o o o r r r r t t t t e e e e d d d d t t t t r r r r a a a a f f f f f f f f i i i i c c c c
MultiNat supports the following IP protocols:
PAT: TCP/UDP traffic which does not carry source or destination IP addresses or ports in the data stream
(i.e., HTTP, telnet, 'r' commands, tftp, NFS, NTP, SMTP, NNTP, etc.).
Static NAT: All IP protocol traffic which does not carry or otherwise rely on the source or destination IP
addresses in the data stream.
Multiple Network Address Translation and IP Setup 10-3
Private Addresses IP Host
192.168.1.1 Router
192.168.1.2 Web Server
192.168.1.3 Mail Server
192.168.1.4 FTP Server #1
192.168.1.5 FTP Server #2
192.168.1.6 - 254 LAN Users
NAT Type
1:1 Static
1:1 Static
1:1 Static
1:1 Static
1:1 Static
1:Many PAT