S R A / S F X 2 1 0 0 S E R I E S S A T E L L I T E R E C E I V E R
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Gateway: 0.0.0.0
Destination: 224.0.0.0
Netmask: 240.0.0.0
7. Local Application Rule 2: Suppose that multicast packets with a destination of
224.1.1.1:1234 are being received from
eth0
and are being forwarded to
eth1
via a
multicast route. If there is no local application running, the packets will be routed
through the system as expected. Now suppose that an application that listens to
224.1.1.1:1234 is started on the receiver (e.g. streaming video). As stated above, a
static route is required for this application to bind to the receiving socket. If this
static route is:
Interface: eth0
Gateway: 0.0.0.0
Destination: 224.1.1.1
Netmask: 255.255.255.255
packets will be routed to
both
the application and eth1. However, if the static route
is:
Interface: eth1
Gateway: 0.0.0.0
Destination: 224.1.1.1
Netmask: 255.255.255.255
then the packets will be routed to the application, but
not
to eth1. If you stop the
application, 224.1.1.1 packets will be output on eth1. If you then restart the
application, output of 224.1.1.1 packets on eth1 will stop.
8. Local Application Rule 3: Suppose that multicast packets with a destination of
224.1.1.1:1234 are being received on
eth0
and are being forwarded to all
interfaces (
eth0
and
eth1
) by a multicast route. Now suppose that an application
that listens to 224.1.1.1:1234 is started on the receiver (e.g. XD). As stated above,
a static route is required for this application to bind to the receiving socket. If this
static route is:
Interface: eth0
Gateway: 0.0.0.0
Destination: 224.1.1.1
Netmask: 255.255.255.255
then the application will get
two
copies of each packet. This anomaly occurs
because Linux forwards one packet to the application immediately when it is
received on the interface and another is received when the kernel routing
subsystem bounces a copy of the packet back to the interface for transmission.
9. Local Application Rule 4: Suppose that multicast packets with a destination of
224.1.1.1:1234 are being received on
sat0
and are being forwarded to all
interfaces (
eth0
and
eth1
) by a multicast route. Now suppose that an application
