Term
| What range of IP addresses is considered the local network control block, aka local scope addresses? |
|
Definition
| 224.0.0.0 through 224.0.0.255 |
|
|
Term
| What range of IP addresses fall under the globally scoped addresses? |
|
Definition
| 224.0.1.0 through 238.255.255.255 |
|
|
Term
| What range of IP addresses fall under the limited, or administratively, scoped addresses? |
|
Definition
| 239.0.0.0 through 239.255.255.255 |
|
|
Term
| What block of Ethernet MAC addresses are reserved for multicast? |
|
Definition
| MAC addresses start with 01:00:5E |
|
|
Term
| What command is used to display IGMP information on a particular interface? |
|
Definition
| show ip igmp interface interface-name |
|
|
Term
| How is CGMP used to ensure that only intended hosts receive multicast packets? |
|
Definition
| The routers inform each of their directly connected switches if IGMP registrations that were received from hosts through the switch. The switch then forwards the multicast traffic only to ports that those requesting hosts are on. |
|
|
Term
| What does a router do when it receives an IGMP control message? |
|
Definition
| It creates a CGMP packet that contains the request type (join or leave), the L2 multicast MAC address, and the actual MAC address of the client. The router then forwards this CGMP packet to all CGMP switches. |
|
|
Term
| Describe how ICMP snooping helps eliminate excessive multicast traffic? |
|
Definition
| With IGMP snooping, the switch eavesdrops on the IGMP message sent between routers and host, and updates its MAC address table accordingly. |
|
|
Term
| Describe the use of Reverse Path Forwarding (RPF) in a multicast network. |
|
Definition
| RPF forwards multicast traffic away from the source, rather than to the receiver. To avoid routing loops, RPF uses the unicast routing table to determine the upstream and downstream neighbors and ensures that only one interface on the router is considered to be an incoming interface for data from a specific source. |
|
|
Term
| What is the difference between PIM's Sparse mode and Dense Mode? |
|
Definition
| Sparse mode uses a "pull" model to send multicast traffic, using a shared tree. Dense mode uses a "push" model that floods multicast traffic to the entire network. They use source trees. |
|
|
Term
| How ofter is the flood and prune process repeated when using PIM-DM? |
|
Definition
| In PIM-DM, all prune messages expire in 3 minutes. |
|
|
Term
| What command enables IP multicasting on a router? |
|
Definition
|
|
Term
| What interface configuration command enables PIM-SM operation on a selected interface? |
|
Definition
|
|
Term
| What interface configuration command enables sparse-dense mode on an interface? |
|
Definition
|
|
Term
| What command configures a router to be an RP? |
|
Definition
| ip pim send-rp-announce interface scope ttl group-list access-list |
|
|
Term
| What command allows a router to join a specified multicast group? |
|
Definition
| ip igmp join-group group-address |
|
|
Term
| What command statically connects and allows a router to become a member of the group? |
|
Definition
| ip igmp static-group group-address |
|
|
Term
| What command displays detailed information on the IP multicast routing table? |
|
Definition
| show ip mroute [group-address] [summary] [count] [active kbps] |
|
|
Term
| What command displays information about interfaces configured for PIM? |
|
Definition
| show ip pim interface [type number] [count] |
|
|
Term
| What command displays the discovered PIM neighbors? |
|
Definition
| show ip pim neighbor [type number] |
|
|
Term
| What command displays information about multicast routers that are peering with the local router or specified router? |
|
Definition
| mrinfo [hostname | address] |
|
|
Term
| What command displays RP information about active groups? |
|
Definition
| show ip pim rp [group-name | group-address | mapping] |
|
|
Term
| What command displays RPF information for the RP or source specified? |
|
Definition
| show ip rpf {address | name} |
|
|
Term
| What command shows multicast-related information about the selected interface? |
|
Definition
| show ip igmp interface [type number] |
|
|
Term
| What command lists the multicast local groups (directly connected) and groups learned via IGMP known to the router? |
|
Definition
| show ip igmp groups [group-address | type number] |
|
|
