Installing and Administering Internet Services

396 Chapter9
Configuring mrouted
Configuring mrouted
alternatively replaced by the interface name, such as lan0. If phyint is
attached to multiple IP subnets, use the altnet option to describe each
additional subnet (one altnet option for each subnet).
The tunnel command can be used to establish a tunnel link between
local IP address local-addr and remote IP address remote-addr (see
figure below). It can also be used to associate a non-default metric or
threshold value with that tunnel. The local IP address local-addr can
be replaced by the interface name, such as lan0. The remote IP address
remote-addr can be replaced by a host name, but only if the host name
has a single IP address associated with it. Before a tunnel can be used,
the tunnel must be set up in the mrouted configuration files of both
mrouted routers participating in the tunnel. Note that, with mrouted
3.8, the srcrt option is no longer supported. (It provided backwards
compatibility with older versions of mrouted that implemented IP
multicast datagram encapsulation using IP source routing.)
NOTE Any phyint commands must precede any tunnel commands. All the
phyint and tunnel command options must be placed on a single line
except for the boundary and altnet options, which can begin on a
separate line.
Figure 9-3 Multicast Network Example Configuration
The metric is the cost, or overhead, associated with sending a datagram
non-multicast
node
node
mrouted
mrouted
phyint 193.3.3.3
193.3.3.3
193.3.4.5
195.5.5.5
tunnel 193.3.4.5 195.5.5.5
boundary 193.3.3.3/16
tunnel 195.5.5.5 193.3.4.5
mrouted
195.5.6.7
router
router
router
phyint 195.5.6.7
node
mrouted
router
node