N o t e
hostname "RouterA"
ip multicast-routing
ip mcast-stub helper-address 10.1.64.1
interface eth 0/1
ip address
10.1.65.1
ip mcast-stub downstream
ip mcast-stub helper-enable
no shutdown
interface t1 1/1
tdm-group 1 timeslots 1-24 speed 64
no shutdown
interface fr 1 point-to-point
frame-relay lmi-type ansi
no shutdown
bind 1 t1 1/1 1 frame-relay 1
interface fr 1.100 point-to-point
frame-relay interface-dlci 100
ip address
10.1.64.2
ip mcast-stub upstream
ip route 0.0.0.0 0.0.0.0 fr 1.100
end
Figure 13-15. Example 1: Router A running-config (IGMP Proxy)
Example 2: Configuring Specific RPs to Support Specific
Groups
The network in Figure 13-16 is similar to that in Example 1. However, Site A
in this network includes a source that multicasts to 239.255.1.1. Because most
hosts for this group will be in the local area, administrators decide to have
Router A act as the RP for this group.
Administrators also decide that the headquarters should have two routers that
can act as RP. Now, if one of the routers fails, hosts at the headquarters can
still receive multicasts. Router D will only support traffic in the 224.0.0.0 /24
range, which enables backup RP support for necessary multicast protocols,
but not for privately defined multicast groups.
Administrators will configure an RP set on each router that includes all three
of the routers selected to act as RPs.
Router D is not a backup RP in the sense that it will only become an RP if the
HQ Router fails. Router D will be the RP for any groups for which the PIM-SM
algorithm selects it.
Configuring Multicast Support with PIM-SM
255.255.255.0
255.255.255.252
Configuring PIM-SM
13-45