OcNOS-SP : Troubleshooting Guide : Multicast
Multicast
This chapter contains steps to resolve multicast issues.
IGMP
IGMP not Active
 
Symptom/Cause
Solution
Multicast routing is not configured
Use these commands:
show ip mvif
Check whether vif is created for the interface.
show ip igmp interface
Check the status of igmp
ip multicast-routing
Configure multicast routing.
Interface is down
Use these commands:
show ip interface brief
Check whether interface has an ip address or the status is down.
ip address A.B.C.D/subnet-mask>
If the address field in the show ip interface brief output shows “unassigned”, configure IP address on the interface with mask. Alternatively, configured ip address can also be checked using “show running-config interface <ifname>”
For ex:
ip address 2.2.2.2/24
no shutdown
Bring up admin status of the interface.
show ip mvif
Check whether vif is created for the interface.
No IGMP configuration exists.
Use these commands:
ip igmp
Configure igmp on the interface
show ip igmp interface
Check whether igmp is enabled.
show running-config interface <ifname>
Verify if igmp is configured.
 
Note: IGMP can also be enabled by pim sparse/dense mode configuration.
Groups not added after Receiving Dynamic Reports
 
Symptom/Cause
Solution
IGMP is not active
Follow the steps above
IGMPv3 report should have one or more sources when the group-record type is INCLUDE
Use this command:
show ip igmp groups
The output displays the added group
Interface is configured as igmp proxy
Use these commands:
show ip igmp proxy
Check whether igmp proxy is enabled.
show running-config interface IFNAME
Check whether “ip igmp proxy service” configuration exists.
IGMP proxy is not active
Verify that IGMP proxy is enabled and active:
show ip igmp proxy
 
Symptom/Cause
Solution
Host interface not configured
Use these commands:
show ip igmp proxy
Check the upstream interface.
show running-config interface IFNAME
Check if the configuration exists.
ip igmp proxy-service
Configure interface as host interface (enable proxy-service).
Mroute-proxy interface not configured
Use these commands:
show ip igmp proxy
Check whether mroute is configured. If there is no output, mroute-proxy is not configured.
ip igmp mroute-proxy upstream-IFNAME
Configure mroute proxy on an interface.
Mismatch between proxy service interface and host interface
Use these commands:
show ip igmp proxy
Check the upstream interface.
show running-config
Check which interface has the proxy-service configured.
ip igmp proxy-service
Configure proxy service on the upstream interface shown by show ip igmp proxy.
IP Multicast routing not configured
Use these commands:
show running-config multicast
Check whether ip multicast routing is configured.
ip multicast-routing
if the configuration is not show in the running-config, use this command to configure ip multicast routing.
Interface is down
Follow the steps explained above
MLD
MLD not Active
Check whether vif is created for the interface:
show ipv6 mif
 
Symptom/Cause
Solution
IPv6 Multicast routing is not configured
Use these commands:
show ipv6 mld interface
Check the status of igmp
ipv6 multicast-routing
Use this command to configure multicast routing.
Interface is down
Use these commands:
show ipv6 interface brief
Check whether interface has an ipv6 address or if the status is down. If the address field is “unassigned”, configure IPv6 address on the interface with mask.
For ex:
ipv6 address 3ffe:506::1/48
no shutdown
Use this command to bring up admin status of the interface.
No MLD configuration exists
Use these commands:
ipv6 mld
Use this command to configure mld on the interface
show ipv6 mld interface
Check whether MLD is enabled.
show running-config interface IFNAME
Verify if mld is configured.
 
Note: MLD can also be enabled by ipv6 pim sparse/dense mode configuration.
Groups not Added on Receiving Dynamic Reports
 
Symptom/Cause
Solution
MLD is not active
Follow the steps above
 
MLDv2 report should have one or more sources when the group-record type is INCLUDE.
show ipv6 mld groups
The output displays the added group
Interface is configured as mld proxy
Use these commands:
show ipv6 mld proxy
Check whether mld proxy is enabled.
show running-config interface IFNAME
Check whether “ipv6 mld proxy service” configuration exists.
MLD Proxy not Active
Verify mld proxy is enabled and active:
show ipv6 mld proxy
 
Symptom/Cause
Solution
Host interface is not configured
Use these commands:
show ipv6 mld proxy
Check the upstream interface.
show running-config interface IFNAME
Check if the configuration exists.
ipv6 mld proxy-service
Configure interface as host interface (enable proxy-service).
Mroute-proxy interface not configured
Use these commands:
show ipv6 mld proxy
Check whether mroute is configured. If there is no output, mroute-proxy is not configured.
ipv6 mld mroute-proxy upstream-IFNAME
Configure mroute proxy on an interface.
Mismatch between proxy service interface and host interface.
Use these commands:
show ipv6 mld proxy
Check the upstream interface.
show running-config
Check which interface has the proxy-service configured.
ipv6 mld proxy-service
Configure proxy service on the upstream interface shown in the “show ip igmp proxy”.
IPv6 Multicast routing not configured
Use these commands:
show running-config multicast
Check whether ipv6 multicast routing is configured.
ipv6 multicast routing
If the configuration is not shown in the running-config, use this command to configure ipv6 multicast routing.
Interface is down
Follow the steps explained above
PIM
RPF Neighbor not Reachable
 
Symptom/Cause
Solution
PIM sparse mode in not configured on the interfaces
Use these commands:
show ip pim neighbor
Check the pim neighbour as the downstream router.
ip pim sparse-mode
Use this command to configure sparse mode on all the concerned interfaces
Multicast routing in not configured
Use this command:
ip multicast-routing
Configure multicast routing on the interface.
Interface is not active
Use these commands:
show ip interface brief
If the address field is “unassigned”, configure IP address on the interface with a mask. Alternatively, configured ip address can also be checked using show running-config interface IFNAME.
For ex:
ip address 2.2.2.2/24
no shutdown
Bring up the admin status of the interface if down.
RPF Interface not What is Expected
 
Symptom/Cause
Solution
Some other route exists.
Use this command:
show ip rpf <source-address>
Check whether RPF interface is as expected; If not some other route exists to the source which is causing the multicast packet to be dropped due to RPF check failure.
RP not Reachable
Check whether an RP is reachable from all the routers in the PIM domain:
show ip pim rp-mapping
 
Symptom/Cause
Solution
RP not configured on all the routers for static RP
Use this command:
ip pim rp-address <RP-address>
Configure rp on all the routers in the pim domain.
VIF for RP is not created
Use these commands:
show ip mvif
Verify whether VIF is created for the RP.
ip pim sparse-mode
If RP is configured on the loopback interface of the router then pim sparse mode configuration must be present on the loopback interface.
ip multicast-routing
Multicast routing must be configured on each router.
Mroute not Created for PIM-SSM
Note: RP configuration is not required for PIM-SSM.
 
Symptom/Cause
Solution
Static group configuration without source
Use these commands:
show ip igmp groups detail
Check whether group recode is include and source list has one or more sources.
no ip igmp static-group <group-addr>
no ip igmp join-group <group-addr>
Remove the static/join group without source, on the interface.
IGMPv2 report present for the group
Use these commands:
show ip igmp groups detail
Group mode should not be exclude. Check whether group mode is exclude; remove the v2 group-record using command below.
clear ip igmp groups <group-addr>
Use this command to remove the igmp v2 group.
MSDP
MSDP Peering not Established
 
Symptom/Cause
Solution
MSDP not configured
Use these commands:
show ip msdp peer
Check whether msdp peering is established.
ip msdp peer <peer-address>
Configure msdp peering on the RPs in different PIM domains.
Password mismatch
Use these commands:
show running-config
Check the configured password for msdp peers.
no ip msdp <wrong-password> peer <peer IP address>
Unconfigure wrong password on the MSDP peer.
ip msdp <password> peer <peer IP address>
Configure the same password as that of its corresponding MSDP peer.