Chapter 5 - IP Multicast and Network Management Flashcards
What does IGMP stand for?
- Interior Group Management Protocol
- Internet Group Management Protocol
- Interior Gateway Routing Protocol
- Interior Gateway Media Protocol
B. You use IGMP between hosts and local routers to register with multicast groups.
How many bits are mapped from the Layer 3 IPv4 multicast address to a Layer 2 MAC address?
- 16 bits
- 23 bits
- 24 bits
- 32 bits
B. The lower 23 bits of the IP multicast address are mapped to the last 23 bits of the Layer 2 MAC address.
Which version of SNMP introduces security extensions for authentication and encryption?
- SNMPv1
- SNMPv2
- SNMPv3
- SNMPv4
C. SNMPv3 introduces authentication and encryption for SNMP.
Which SNMP component contains an agent?
- Managed device
- Agent
- NMS manager
- MIB
A. Managed devices contain SNMP agents.
Which of the following is correct regarding an OOB management network?
- It can be used as a backup network.
- It uses the same infrastructure as the primary network.
- It uses a separate physical network.
- It provides no segmentation.
C. An OOB management network uses separate infrastructure.
Which multicast protocol eliminates the RP and shared trees?
- PIM-SM
- BIDIR-PIM
- SSM
- MSDP
C. SSM eliminates the RPs and shared trees and only builds a SPT.
The Source Specific Multicast feature is an extension of IP Multicast where datagram traffic is forwarded to receivers from only those multicast sources to which the receivers have explicitly joined.
Which SNMP operation obtains full table information from an agent?
- Get
- GetNext
- GetBulk
- Inform
C. The NMS manager uses the GetBulk operation to retrieve large blocks of data, such as multiple rows in a table.
RMON1 provides information at what levels of the OSI model?
- Data link and physical
- Network, data link, and physical
- Transport and network
- Application to network
A. RMON1 is focused on the data link and physical layers of the OSI model.
Which of the following is not an SNMP operation?
- Get
- Community
- Set
- Trap
B. Community is not an SNMP operation.
Which are called shortest-path trees (SPTs)?
- Source trees
- Shared trees
- Spanning trees
- Routing trees
A. Source trees are also called shortest-path trees (SPTs) because they create paths without having to go through a rendezvous point (RP).
True or false: IGMP snooping and CGMP are methods to reduce the multicast traffic at Layer 2.
True.
IGMP snooping is an IP multicast constraining mechanism that runs on a Layer 2 LAN switch. IGMP snooping requires the LAN switch to examine, or “snoop,” some Layer 3 information (IGMP Join/Leave messages) in the IGMP packets sent between the hosts and the router.
When the switch receives the IGMP host report from a host for a particular multicast group, the switch adds the port number of the host to the associated multicast table entry. When the switch hears the IGMP Leave group message from a host, the switch removes the table entry of the host.
True or false: PIM has a hop count limit of 32.
False. PIM does not have a hop count limit. DVMRP has a hop count limit of 32.
The Distance Vector Multicast Routing Protocol (DVMRP) is a routing protocol used to share information between routers to facilitate the transportation of IP multicast packets among networks.
True or false: PIM-SM routers use the multicast address 224.0.0.13 to request a multicast group from the RP.
True.
- Match each IP multicast address with its description.
- 224.0.0.1
- 224.0.0.2
- 224.0.0.5
- 224.0.0.10
- All OSPF routers
- All routers
- EIGRP routers
- All hosts
i = D
ii = B
iii = A
iv = C
- Match each IPv6 multicast address with its description.
- FF02::1
- FF02::2
- FF02::5
- FF02::9
- FF02::A
- OSPFv3 routers
- RIPng routers
- All routers
- EIGRP routers
- All nodes
- FF02::1 - All nodes
- FF02::2 - All routers
- FF02::5 - All OSPF routers
- FF02::9 - RIPng routers
- FF02::A - EIGRP for IPv6 routers
Note: FF02 is the ‘link-local scope’
Remember that FF01 is the ‘interface-local scope’
PIM-SM is configured on the network. Which protocol prevents media streams from being broadcast on the access switch?
- PIM-SM
- RD
- IGMPv3
- Auto-RP
- IGMP snooping
D.
Multicast PIM sparse mode requires an RP (Rendezvous Point) as a meeting point in the network for all multicast traffic. These RPs must be manually configured the on all routers.
Luyckily, there are two discovery protocols that we can use to automatically find an RP on the network:
- Auto-RP
- PIMv2 bootstrap router (BSR)
Auto-RP is a Cisco proprietary protocol that uses two different roles:
- Candidate RP
- Mapping Agent
The candidate RP is a router that announces itself that it wants to be an RP for the network. It does so by sending RP announcement packets to the 224.0.1.39 multicast address.
The mapping agent listens to the RP announcement packets from our RP candidates and makes a list of all possible RPs. It will then elect an RP and informs the rest of the network with RP mapping packets that are sent to multicast address 224.0.1.40.
CDP runs at what layer of the OSI model?
Data link layer.
What is the name of syslog level 5 severity?
Notice level.
“Ernie Always Cries, Even When Nobody Is Dying.”
Emergency, Alert, Critical, Error, Warning, Notification, Informational, Debug.
True or false: RMON provides more scalability than NetFlow.
False.
True or false: NetFlow provides detailed information on the number of bytes and packets per conversation.
True.
What information can be obtained from a neighbor by using CDP?
Device ID, IP address, capabilities, OS version, model number, and port ID.
What SNMP message is sent by an agent when an event occurs?
- Get
- Set
- GetResponse
- Trap
D. A trap message is sent by the agent when a significant event occurs.
What SNMP message is sent to an agent to obtain an instance of an object?
- Get
- Set
- GetResponse
- Trap
A. The NMS manager uses the Get operation to retrieve the value-specific MIB variable from an agent.
What SNMP message is used to configure a managed device?
- Get
- Set
- GetResponse
- Trap
B. The NMS manager uses the Set operation to set values of the object instance within an agent.

