HP-UX LAN Administrator's Guide (Feburary 2007)

Network AddressingDRAFT COPY
IP Multicast Addresses
Chapter 7134
NOTE Several IP multicast addresses may share the same Ethernet multicast address
because the IP multicast address has 28 significant bits.
Multicast Routing
Multicast datagrams are sent through the interface associated with the default route. If that
interface does not support multicast, attempts to send multicast datagrams will result in the
ENETUNREACH error.
A default multicast route can be configured by specifying a network route for 224.0.0.0. The
example below provides both the command line and netconf file entries.
route add 224.0.0.0 192.1.2.3 0 #192.1.2.3 is a local interface
ROUTE_DESTINATION[1]=”224.0.0.0”
ROUTE_GATEWAY[1]=”192.1.2.3”
ROUTE_COUNT[1]=”0”
Additionally, routes for specific multicast addresses can be configured just like any other host
route. The example below provides both the command line and netconf file entries.
route add 224.1.2.3 192.5.6.7 0 #192.5.6.7 is a local interface
ROUTE_DESTINATION[2]=”224.1.2.3”
ROUTE_GATEWAY[2]=”192.5.6.7”
ROUTE_COUNT[2]=”0”