IP Multicast

A network engineer is troubleshooting multicast video distribution across an enterprise campus. The multicast source is connected to a switch that is the PIM Designated Router (DR) on a multi-access segment. Receivers in a different VLAN report that they are not receiving the multicast stream, although the DR shows the correct (S,G) entry. The engineer checks the RPF neighbor for the source and notices that the unicast route to the source points to a different interface than the one where the multicast stream is received. What is the most likely cause of the issue?

Question 3mediummultiple choice

A network engineer is deploying IP multicast in an OSPF-based enterprise network. The network uses PIM sparse mode with a static RP. The engineer notices that multicast traffic from a source to a group is not reaching receivers in a remote subnet, even though the RP is reachable and the receivers have sent IGMP joins. The engineer checks the multicast routing table on the last-hop router and sees that the (S,G) entry is present, but the outgoing interface list (OIL) is empty. What is the most likely reason for the empty OIL?

Question 4hardmultiple choice

An engineer is configuring multicast on a Cisco router running IOS-XE. The network uses PIM sparse mode with a static RP at 10.1.1.1. The engineer enters the command 'ip pim rp-address 10.1.1.1' but multicast traffic is not being forwarded. Upon verification, the engineer sees that the RP is reachable via OSPF, but the 'show ip pim rp mapping' command does not list any RP for the group. What is the most likely cause?

Question 5hardmultiple choice

A network engineer is troubleshooting multicast connectivity in a large enterprise. The network uses PIM sparse mode with Auto-RP. The engineer notices that some routers are not receiving the RP mapping for a particular group. The engineer checks the Auto-RP mapping agent and sees that it is sending RP announcements, but the routers that are missing the mapping are not in the same PIM domain. What is the most likely reason?

Question 6mediummultiple choice

An engineer is configuring multicast on a Cisco switch running IOS. The switch is acting as the IGMP querier for a VLAN. The engineer notices that multicast traffic is being flooded to all ports in the VLAN, even though only a few receivers have joined the group. The engineer checks the IGMP snooping configuration and sees that IGMP snooping is enabled globally and on the VLAN. What is the most likely cause of the flooding?

Question 7hardmultiple choice

A network engineer is configuring PIM sparse mode in a network that uses a Bootstrap Router (BSR) for RP discovery. The engineer has configured a candidate BSR and candidate RPs. However, some routers in the network are not learning the RP set. The engineer checks the BSR and sees that it is receiving candidate RP advertisements, but the BSR messages are not being forwarded to all routers. What is the most likely cause?

Question 8mediummultiple choice

An engineer is troubleshooting multicast performance issues. The network uses PIM sparse mode with a static RP. The engineer notices that the multicast traffic from a source to a group is taking a suboptimal path, causing high latency. The engineer checks the multicast routing table on the last-hop router and sees that the (S,G) entry has an incoming interface that is not the shortest path to the source. What is the most likely reason for this suboptimal path?

Question 9easymultiple choice

A network engineer is configuring multicast on a Cisco router that connects to a multi-access network. The engineer wants to ensure that only one router forwards multicast traffic onto the segment to avoid duplication. The engineer enables PIM on the interface. However, multicast traffic is still being duplicated on the segment. What is the most likely reason?

Question 10easymultiple choice

An engineer is configuring multicast on a Cisco router. The router receives multicast traffic from a source on interface GigabitEthernet0/0 and needs to forward it to receivers on interface GigabitEthernet0/1. The engineer enables PIM sparse mode on both interfaces and configures a static RP. However, the router does not create a multicast routing entry for the (S,G) pair. What is the most likely missing configuration?

Question 11mediummultiple choice

A network engineer runs the following command on Router R1:

R1# show ip pim neighbor

PIM Neighbor Table

Neighbor Address  Interface           Uptime    Expires   Mode
10.1.1.2          GigabitEthernet0/0  2w0d      00:01:25  DR
10.1.1.3          GigabitEthernet0/0  2w0d      00:01:20  B

Based on this output, what can be concluded?

Question 12mediummultiple choice

A network engineer issues the following command on Router R2:

R2# show ip mroute 239.1.1.1
IP Multicast Routing Table

Flags: D - Dense, S - Sparse, B - Bidir Group, s - SSM Group, C - Connected, L - Local, P - Pruned, R - RP-bit set, F - Register flag, T - SPT-bit set, J - Join SPT, M - MSDP created entry, E - Extranet, X - Proxy Join Timer Running, A - Candidate for MSDP Advertisement, U - URD, I - Received Source Specific Host Report, Z - Multicast Tunnel, z - MDT-data group session, Y - Joined MDT-data group, y - Sending to MDT-data group Outgoing interface flags: H - Hardware switched, A - Assert winner Timers: Uptime/Expires

Interface state: Interface, Next-Hop or VCD, State/Mode

(*, 239.1.1.1), 00:03:45/00:02:15, RP 10.0.0.1, flags: S Incoming interface: GigabitEthernet0/0, RPF nbr 10.0.0.1 Outgoing interface list: GigabitEthernet0/1, Forward/Sparse, 00:03:45/00:02:15

Based on this output, what can be concluded?

Question 13mediummultiple choice

A network engineer executes the following command on Router R3:

R3# show ip igmp groups 239.2.2.2

IGMP Connected Group Membership Group Address Interface Uptime Expires Last Reporter

239.2.2.2        GigabitEthernet0/0       1d04h     00:02:10  192.168.1.100

Based on this output, what can be concluded?

Question 14hardmultiple choice

A network engineer runs the following command on Router R4:

R4# show ip pim rp mapping

PIM Group-to-RP Mappings This system is an RP (Auto-RP) This system is an RP (BSR) Group(s) 224.0.0.0/4 RP 10.0.0.2 (?), v2v1 Info source: 10.0.0.2 (?), elected via Auto-RP, expires in 00:01:30 RP 10.0.0.3 (?), v2v1 Info source: 10.0.0.3 (?), elected via BSR, expires in 00:02:00

Based on this output, what can be concluded?

Question 15mediummultiple choice

A network engineer issues the following command on Router R5:

R5# show ip pim interface
Interface          PIM  Nbrs  Hello  DR    DR

Count Intvl Prior GigabitEthernet0/0 on 2 30 1 10.1.1.1 GigabitEthernet0/1 on 1 30 1 10.2.2.2 Loopback0 on 0 30 1 10.3.3.3

Based on this output, what can be concluded?

Question 16mediummultiple choice

A network engineer runs the following command on Router R6:

R6# show ip pim rp 239.3.3.3

RP 10.0.0.4

Info source: 10.0.0.4, via bootstrap, priority 192, holdtime 150, expires in 00:02:30

Based on this output, what can be concluded?

Question 17hardmultiple choice

A network engineer issues the following command on Router R7:

R7# show ip pim tunnel

Tunnel1: Type: PIM Encap Source: 10.0.0.7, Destination: 10.0.0.8 Status: up

Based on this output, what can be concluded?

Question 18mediummultiple choice

A network engineer runs the following command on Router R8:

R8# show ip mroute count
IP Multicast Statistics

Group: 239.4.4.4, Source: 10.0.0.9 Packets: 1500, Bytes: 1200000, Average rate: 8000 pps, 5 sec rate: 0 pps

Group: 239.5.5.5, Source: 10.0.0.10 Packets: 0, Bytes: 0, Average rate: 0 pps, 5 sec rate: 0 pps

Based on this output, what can be concluded?

Question 19hardmultiple choice

A network engineer issues the following command on Router R9:

R9# show ip pim bsr-router

PIMv2 Bootstrap Router (BSR) information This system is the Bootstrap Router (BSR) BSR address: 10.0.0.11 Uptime: 1w2d, BSR priority: 0, Hash mask length: 30 Next bootstrap message in 00:00:45

Based on this output, what can be concluded?

Question 20mediummultiple choice

Consider the following configuration snippet on a Cisco IOS-XE router:

interface GigabitEthernet0/1
 ip address 10.1.1.1 255.255.255.0
 ip pim sparse-mode
 ip igmp version 3

router ospf 1
 network 10.1.1.0 0.0.0.255 area 0

What is the effect of this configuration?

Question 21mediummultiple choice

Examine the following configuration on a Cisco IOS-XE router:

ip multicast-routing distributed

interface GigabitEthernet0/0
 ip address 192.168.1.1 255.255.255.0
 ip pim sparse-dense-mode
 ip igmp version 2

Which statement about this configuration is true?

Question 22mediummultiple choice

Given the following partial configuration on a Cisco IOS-XE router:

ip pim rp-address 10.0.0.1 10
access-list 10 permit 224.0.0.0 0.255.255.255

interface GigabitEthernet0/0
 ip pim sparse-mode

What is the effect of this configuration?

Question 23mediummultiple choice

Consider the following configuration on a Cisco IOS-XE router:

ip multicast-routing

interface GigabitEthernet0/0
 ip address 10.0.0.1 255.255.255.0
 ip pim sparse-mode
 ip igmp static-group 239.1.1.1

What is the effect of the 'ip igmp static-group 239.1.1.1' command?

Question 24mediummultiple choice

Examine the following configuration snippet:

ip pim send-rp-announce Loopback0 scope 10 group-list 10
ip pim send-rp-discovery scope 10
access-list 10 permit 239.0.0.0 0.255.255.255

interface Loopback0
 ip address 192.168.0.1 255.255.255.255
 ip pim sparse-mode

What is the purpose of this configuration?

Question 25mediummultiple choice

Given the following configuration on a Cisco IOS-XE router:

ip multicast-routing

interface GigabitEthernet0/0
 ip address 10.1.1.1 255.255.255.0
 ip pim sparse-mode
 ip igmp version 2

router ospf 1
 network 10.1.1.0 0.0.0.255 area 0

What is missing from this configuration to support Source-Specific Multicast (SSM) for group range 232.0.0.0/8?

Question 26easymultiple choice

What is the default IGMP version on a Cisco IOS interface when IP multicast routing is enabled?

Question 27easymultiple choice

Which PIM mode requires a rendezvous point (RP) to function?

Question 28mediummultiple choice

What is the default multicast group range for Source-Specific Multicast (SSM) as defined by IANA and supported by Cisco IOS?

Question 29mediumdrag order

Drag and drop the steps of PIM-SM join and source registration into the correct order, from first to last.

Question 30mediumdrag order

Drag and drop the steps of RPF check verification for multicast forwarding into the correct order, from first to last.

Question 31mediumdrag order

Full Practice Test →All Objectives

Drag and drop the steps of IGMPv3 membership report processing into the correct order, from first to last.

More IP Multicast questions available in the full practice test.

Continue Practising →

Objective 311.0

IP Multicast

350-401 Practice Questions

350-401 IP Multicast — Practice Questions

30 questions from this objective

Question 2mediummultiple choice

A network engineer is troubleshooting multicast video distribution across an enterprise campus. The multicast source is connected to a switch that is the PIM Designated Router (DR) on a multi-access segment. Receivers in a different VLAN report that they are not receiving the multicast stream, although the DR shows the correct (S,G) entry. The engineer checks the RPF neighbor for the source and notices that the unicast route to the source points to a different interface than the one where the multicast stream is received. What is the most likely cause of the issue?

Question 3mediummultiple choice

A network engineer is deploying IP multicast in an OSPF-based enterprise network. The network uses PIM sparse mode with a static RP. The engineer notices that multicast traffic from a source to a group is not reaching receivers in a remote subnet, even though the RP is reachable and the receivers have sent IGMP joins. The engineer checks the multicast routing table on the last-hop router and sees that the (S,G) entry is present, but the outgoing interface list (OIL) is empty. What is the most likely reason for the empty OIL?

Question 4hardmultiple choice

An engineer is configuring multicast on a Cisco router running IOS-XE. The network uses PIM sparse mode with a static RP at 10.1.1.1. The engineer enters the command 'ip pim rp-address 10.1.1.1' but multicast traffic is not being forwarded. Upon verification, the engineer sees that the RP is reachable via OSPF, but the 'show ip pim rp mapping' command does not list any RP for the group. What is the most likely cause?

Question 5hardmultiple choice

A network engineer is troubleshooting multicast connectivity in a large enterprise. The network uses PIM sparse mode with Auto-RP. The engineer notices that some routers are not receiving the RP mapping for a particular group. The engineer checks the Auto-RP mapping agent and sees that it is sending RP announcements, but the routers that are missing the mapping are not in the same PIM domain. What is the most likely reason?

Question 6mediummultiple choice

An engineer is configuring multicast on a Cisco switch running IOS. The switch is acting as the IGMP querier for a VLAN. The engineer notices that multicast traffic is being flooded to all ports in the VLAN, even though only a few receivers have joined the group. The engineer checks the IGMP snooping configuration and sees that IGMP snooping is enabled globally and on the VLAN. What is the most likely cause of the flooding?

Question 7hardmultiple choice

A network engineer is configuring PIM sparse mode in a network that uses a Bootstrap Router (BSR) for RP discovery. The engineer has configured a candidate BSR and candidate RPs. However, some routers in the network are not learning the RP set. The engineer checks the BSR and sees that it is receiving candidate RP advertisements, but the BSR messages are not being forwarded to all routers. What is the most likely cause?

Question 8mediummultiple choice

An engineer is troubleshooting multicast performance issues. The network uses PIM sparse mode with a static RP. The engineer notices that the multicast traffic from a source to a group is taking a suboptimal path, causing high latency. The engineer checks the multicast routing table on the last-hop router and sees that the (S,G) entry has an incoming interface that is not the shortest path to the source. What is the most likely reason for this suboptimal path?

Question 9easymultiple choice

A network engineer is configuring multicast on a Cisco router that connects to a multi-access network. The engineer wants to ensure that only one router forwards multicast traffic onto the segment to avoid duplication. The engineer enables PIM on the interface. However, multicast traffic is still being duplicated on the segment. What is the most likely reason?

Question 10easymultiple choice

An engineer is configuring multicast on a Cisco router. The router receives multicast traffic from a source on interface GigabitEthernet0/0 and needs to forward it to receivers on interface GigabitEthernet0/1. The engineer enables PIM sparse mode on both interfaces and configures a static RP. However, the router does not create a multicast routing entry for the (S,G) pair. What is the most likely missing configuration?

Question 11mediummultiple choice

A network engineer runs the following command on Router R1:

R1# show ip pim neighbor

PIM Neighbor Table

Neighbor Address  Interface           Uptime    Expires   Mode
10.1.1.2          GigabitEthernet0/0  2w0d      00:01:25  DR
10.1.1.3          GigabitEthernet0/0  2w0d      00:01:20  B

Based on this output, what can be concluded?

Question 12mediummultiple choice

A network engineer issues the following command on Router R2:

R2# show ip mroute 239.1.1.1
IP Multicast Routing Table

Interface state: Interface, Next-Hop or VCD, State/Mode

(*, 239.1.1.1), 00:03:45/00:02:15, RP 10.0.0.1, flags: S Incoming interface: GigabitEthernet0/0, RPF nbr 10.0.0.1 Outgoing interface list: GigabitEthernet0/1, Forward/Sparse, 00:03:45/00:02:15

Based on this output, what can be concluded?

Question 13mediummultiple choice

A network engineer executes the following command on Router R3:

R3# show ip igmp groups 239.2.2.2

IGMP Connected Group Membership Group Address Interface Uptime Expires Last Reporter

239.2.2.2        GigabitEthernet0/0       1d04h     00:02:10  192.168.1.100

Based on this output, what can be concluded?

Question 14hardmultiple choice

A network engineer runs the following command on Router R4:

R4# show ip pim rp mapping

Based on this output, what can be concluded?

Question 15mediummultiple choice

A network engineer issues the following command on Router R5:

R5# show ip pim interface
Interface          PIM  Nbrs  Hello  DR    DR

Count Intvl Prior GigabitEthernet0/0 on 2 30 1 10.1.1.1 GigabitEthernet0/1 on 1 30 1 10.2.2.2 Loopback0 on 0 30 1 10.3.3.3

Based on this output, what can be concluded?

Question 16mediummultiple choice

A network engineer runs the following command on Router R6:

R6# show ip pim rp 239.3.3.3

RP 10.0.0.4

Info source: 10.0.0.4, via bootstrap, priority 192, holdtime 150, expires in 00:02:30

Based on this output, what can be concluded?

Question 17hardmultiple choice

A network engineer issues the following command on Router R7:

R7# show ip pim tunnel

Tunnel1: Type: PIM Encap Source: 10.0.0.7, Destination: 10.0.0.8 Status: up

Based on this output, what can be concluded?

Question 18mediummultiple choice

A network engineer runs the following command on Router R8:

R8# show ip mroute count
IP Multicast Statistics

Group: 239.4.4.4, Source: 10.0.0.9 Packets: 1500, Bytes: 1200000, Average rate: 8000 pps, 5 sec rate: 0 pps

Group: 239.5.5.5, Source: 10.0.0.10 Packets: 0, Bytes: 0, Average rate: 0 pps, 5 sec rate: 0 pps

Based on this output, what can be concluded?

Question 19hardmultiple choice

A network engineer issues the following command on Router R9:

R9# show ip pim bsr-router

PIMv2 Bootstrap Router (BSR) information This system is the Bootstrap Router (BSR) BSR address: 10.0.0.11 Uptime: 1w2d, BSR priority: 0, Hash mask length: 30 Next bootstrap message in 00:00:45

Based on this output, what can be concluded?

Question 20mediummultiple choice

Consider the following configuration snippet on a Cisco IOS-XE router:

interface GigabitEthernet0/1
 ip address 10.1.1.1 255.255.255.0
 ip pim sparse-mode
 ip igmp version 3

router ospf 1
 network 10.1.1.0 0.0.0.255 area 0

What is the effect of this configuration?

Question 21mediummultiple choice

Examine the following configuration on a Cisco IOS-XE router:

ip multicast-routing distributed

interface GigabitEthernet0/0
 ip address 192.168.1.1 255.255.255.0
 ip pim sparse-dense-mode
 ip igmp version 2

Which statement about this configuration is true?

Question 22mediummultiple choice

Given the following partial configuration on a Cisco IOS-XE router:

ip pim rp-address 10.0.0.1 10
access-list 10 permit 224.0.0.0 0.255.255.255

interface GigabitEthernet0/0
 ip pim sparse-mode

What is the effect of this configuration?

Question 23mediummultiple choice

Consider the following configuration on a Cisco IOS-XE router:

ip multicast-routing

interface GigabitEthernet0/0
 ip address 10.0.0.1 255.255.255.0
 ip pim sparse-mode
 ip igmp static-group 239.1.1.1

What is the effect of the 'ip igmp static-group 239.1.1.1' command?

Question 24mediummultiple choice

Examine the following configuration snippet:

ip pim send-rp-announce Loopback0 scope 10 group-list 10
ip pim send-rp-discovery scope 10
access-list 10 permit 239.0.0.0 0.255.255.255

interface Loopback0
 ip address 192.168.0.1 255.255.255.255
 ip pim sparse-mode

What is the purpose of this configuration?

Question 25mediummultiple choice

Given the following configuration on a Cisco IOS-XE router:

ip multicast-routing

interface GigabitEthernet0/0
 ip address 10.1.1.1 255.255.255.0
 ip pim sparse-mode
 ip igmp version 2

router ospf 1
 network 10.1.1.0 0.0.0.255 area 0

What is missing from this configuration to support Source-Specific Multicast (SSM) for group range 232.0.0.0/8?

Question 26easymultiple choice

What is the default IGMP version on a Cisco IOS interface when IP multicast routing is enabled?

Question 27easymultiple choice

Which PIM mode requires a rendezvous point (RP) to function?

Question 28mediummultiple choice

What is the default multicast group range for Source-Specific Multicast (SSM) as defined by IANA and supported by Cisco IOS?

Question 29mediumdrag order

Drag and drop the steps of PIM-SM join and source registration into the correct order, from first to last.

Question 30mediumdrag order

Drag and drop the steps of RPF check verification for multicast forwarding into the correct order, from first to last.

Question 31mediumdrag order