Lancom Systems LCOS 3.50 - Manual (Page 85)

̈ Chapter 7: Routing and WAN connections LANCOM Reference Manual LCOS 3.50
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Routing and
W
A
N
con
n
ections
head office. On this occasion, also all subnetworks located “behind” the
head office are supplied with the needed new IP addresses.
In this example, the administrator of the service provider selects 10.2.x.x as
central address translation for the network of client B, so that both networks
with actual same address range looks like two different networks for the gate-
way of the service provider.
The administrator selects the address ranges 192.168.2.x and 192.168.3.x for
client C and D, so that the addresses of these networks do differ from the own
network of the service provider.
In order to enable the gateway of the provider to monitor the networks of cli-
ents C and D, the administrator sets up an address translation to 192.168.1.x
also for the own network.
7.4.2 Configuration
Setting up address translation
Configuration of N:N mapping succeeds with only few information. Since a
LAN can be coupled with several other networks via N:N, different destina-
tions can have also different address translations for a source IP range. The
NAT table can contain 64 entries at maximum, including the following infor-
mation:
̈ Index: Unambiguous index of the entry.
̈ Source address: IP address of the workstation or network that should
get an alternative IP address.
̈ Source mask: Netmask of source range.
̈ Remote station: Name of the remote station over that the remote net-
work is reachable.
̈ New network address: IP address or address range that should be used
for the translation.
For the new network address, the same netmask will be used as the source
address already uses. For assignment of source and mapping addresses the
following hints apply:
̈ Source and mapping can be assigned arbitrarily for the translation of sin-
gle addresses. Thus, for example, it is possible to assign the mapping
address 192.168.1.88 to a LAN server with the IP address 10.1.1.99.
̈ For translation of entire address ranges, the station-related part of the IP
address will be taken directly, only appended to the network-related part