Seneca S6001-RTU, Руководство пользователя

Страница: 53 / 210

USER MANUAL – Z-TWS4/Z-PASS2-S/S6001-RTU
53
12 Router
As already told before, “Router” functionality routes packets between the WAN (Mobile Network) interface
and the LAN (Ethernet) interface and vice versa; so, this functionality especially makes sense when a 3G
connection is active, which needs the availability of a 3G modem (true for Z-PASS2-S and S6001-RTU).
More specifically, an important feature of the Router is what is known as “IP forwarding”; this means that
when the Device receives a packet not targeted for it, it does not discard the packet but forwards it to its
actual destination; when a packet is routed from the LAN to the WAN, the Device also performs what is
known as “IP masquerading”, meaning that the original source IP address is replaced with the IP address of
the WAN (Mobile Network) interface.
Another important feature is the availability of a DNS server/forwarder, which can resolve names either by
itself or querying the external configured DNS server.
Also, a DHCP server is available which assigns IP addresses to clients connected on the Device LAN; here,
you can configure the range of addresses used by the server and the lease time.
There is also the possibility to define up to five “Port Forwarding” rules or “Virtual Servers”; using these
rules, you can, for example, redirect packets received on a TCP or UDP port to another Device port or to
another machine, with a different IP address, on the same or another port.
As an alternative to using “Port Forwarding” rules, Router + VPN functionalities allow the use of local
addresses, as shown in the previous chapter; in the router configuration, a flag is given to enable this
feature.
A detailed description of the Router configuration can be found in paragraph 18.1.5.