Netopia 4000 Series, Software Manual

Page: 71 / 314

Multiple Network Address Translation 3-5
Complex maps
Map lists and ser ver lists are completely independent of each other. A Connection Profile can use one or the
other or both.
MultiNAT allows complex mapping and requires more complex configuration than in earlier firmware versions.
Multiple mapped interior subnets are suppor ted, and the rules for mapping each of the subnets may be
different. The figure below illustrates a possible multiNAT configuration.
In order to suppor t 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 par ticular resource is not available, subordinate
mappings can be defined that will redirect traffic.
Supported traffic
MultiNat suppor ts the following IP protocols:
■ PAT: TCP/UDP traffic which does not carr y source or destination IP addresses or por ts 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 carr y or other wise rely on the source or destination IP
addresses in the data stream.
■ Dynamic NAT: All IP protocol traffic which does not carr y or other wise rely on the source or destination IP
addresses in the data stream.
Support for Microsoft Network (MSN) Messenger
Netopia Firmware Version 5.4 provides suppor t for MSN Messenger/Windows Messenger applications via UPnP
(see
UPnP Suppor t on page 10-2 ). Normal plain chat always works.
Support for AOL Instant Messenger (AIM) File Transfer
Netopia Firmware Version 5.4 provides Application Level Gateway (ALG) suppor t for AOL Instant Messenger
(AIM) file transfer. This allows AIM users to exchange files, even when both users are behind NAT. Previously,
the file transfer function would work only if one or neither of the two users were behind NAT.
Private Addresses IP Host Public 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
1:1 Static
206.1.1.5
206.1.1.6
192.168.1.1 – 252
192.168.1.1 – 252
Web/FTP Ser ver
E-mail Ser ver
1:1 Dynamic
1:1 Dynamic
LAN Users
LAN Users
206.1.2.1 – 6 LAN Users
1:Many PAT
(possible later)
192.168.1.1
}
192.168.1.1 – 252