Installing and Administering Internet Services

312 Chapter 9

Conﬁguring mrouted

The cache_lifetime value determines the amount of time that a

cached multicast route remains in the kernel before timing out. This

value is speciﬁed in seconds and should be between 300 (5 minutes) and

86400 (24 hours). The default value is 300.

The pruning off command explicitly conﬁgures mrouted to act as a

“non-pruning” router. When pruning is off, IP multicast datagrams are

forwarded to leaf subnets of the broadcast routing tree even when those

leaf subnets do not contain members of the multicast destination group.

Non-pruning mode should be used only for testing. The default mode for

pruning is on.

The name command enables you to assign a name (boundary-name) to a

boundary (a scoped-addr/mask-len pair), which can make conﬁguration

easier.

mrouted will terminate execution if it has less than two enabled virtual

interfaces (vifs), where a vif is either a physical multicast-capable

interface or a tunnel. It logs a warning if all of its vifs are tunnels. If this

happens, we recommend that you replace that conﬁguration with more

direct tunnels.