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Local IP/network
Viewed from the perspective of the selected interface, you can enter a local
address here. This corresponds to the source IP of outbound packets (before
SNAT) and the destination IP of inbound packets (before DNAT).
When SNAT or DNAT is involved, restricting a priority rule
to specific local IPs usually requires two rules to catch both,
in- and outbound packets: For inbound packets you would
enter a SX-GATE IP, for outbound packets the internal IP
(of the LAN client or the server addressed with DNAT).
Direction
Decide in which direction the port signature of the selected protocol has to be
applied. Let's take the HTTP protocol as an example. The arrow "-->" means
the HTTP port 80 is on the external side. So outbound bandwidth management
will process packets to port 80, inbound bandwidth management packets from
port 80. With "-->" you will get the opposite: Packets to port 80 are processed by
inbound, packets from port 80 by outbound bandwidth management. The double
arrow "
↔
" combines both directions.
External IP/network
Viewed from the perspective of the selected interface, you can enter a remote
address here. This corresponds to the destination IP of outbound packets and the
source IP of inbound packets.
Priority
Select the priority for matching packets.
14.1.2.1-F
Dynamic DNS
With dynamic DNS it is possible to address a device which it is connected to the Internet
with a dynamic IP address. Using this feature with SX-GATE, you can get access to
the services offered by SX-GATE despite of its dynamic IP address.
Of course it is not possible to access SX-GATE from the Internet
if the dial-up link is offline. Also SX-GATE must be assigned a
"valid" Internet IP, i.e. it must not be situated behind an upstream
NAT router.
With dynamic DNS, ordinary hostnames (fully qualified domain names, FQDN) are
used to address SX-GATE. This hostname will resolve to the current dynamic IP of SX-
GATE. To enable this, SX-GATE has to update its dynamic DNS record everytime a
new dial-up connection is established.
