5 Configure with NetCom Manager
5.6.2 SOHO Virtual Servers
The Router also offers "Virtual Servers" (here named ViServ for short), which is the option required
for NetCom
+
installation. These ViServ operate by a technique called PAT (Port Address Trans-
lation,
15
). Certain data addressed to the public IP Address of the Router are forwarded to the
internal private address of the NetCom
+
. This way the NetCom
+
can be contacted via the public
IP Address of the Router.
First you need to configure the Router for some ViServs. As the absolute minimum there is one
ViServ for the NetCom
+
device itself, and another two ViServs for each serial port of the NetCom
+
.
Those ViServs are to be configured for TCP or UDP transmissions. Please read in the manual of
your Router how to do that. You need a port for the external interface, and an IP Address plus a
port for the LAN side. The LAN IP Address is of course that of the NetCom
+
. As an example the
most easy device is a NetCom
+
113 PRO. The internal port for SNMP is 161 for UDP. The serial
port requires ports 2000 and 2001 for TCP.
Function
External port
Internal port
SNMP
8161/UDP
161/UDP
Control
9000/TCP
2000/TCP
Data
9001/TCP
2001/TCP
Table 18: SOHO Firewall Pass-Through
Configure your Router for these example ViServs, and use the internal IP Address of the NetCom
+
for the targets. Connect the NetCom
+
to your LAN. Now you are ready for a very first test. Use
Telnet to connect to the Data port of the NetCom
+
serial port. Open a console (DOS Box) and
type the command
Telnet <Routers-IP-Address> 9001
You will be connected to the serial port. Every character you type is sent out of the serial port,
and every received data is shown on your screen. The serial parameters are pre-configured in your
NetCom
+
.
5.6.3 NetCom Detection through SOHO Firewall
Now open the NetCom Manager as in section
5.5
above, and click the
Add
button. You again get the
NetCom Manager Server Settings dialog. But now you have to select the panel named
Firewall
(see figure
53
).
Check the Option
Enable Firewall
, and enter the IP Address of the Router in the
Address
field. In
the field
Port
enter the target port for the SNMP configuration. From the Virtual Server example
above this is port 8161. Since there is no configured ViServ for Logging, ignore this field. Click
the button
Verify
to have the NetCom Manager contact the Router. This is a directed request,
so there is no problem with broadcasts. The Router will transfer the request to UDP-Port 161 on
the NetCom
+
, which is the port for SNMP. The NetCom
+
will answer the request, and send it out
to your computer. The NAT function in the Router will replace the source IP of the data by its
own public value, so the NetCom Manager will see the answer come from the Router. The NetCom
Manager is satisfied with this data.
September 2016
NetCom Plus User Manual
56
Summary of Contents for NetCom Plus 111
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