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Cisco Bug: CSCtf21128 - (S, G) fwd int is NULL while (*, G) is correct

Last Modified

Apr 03, 2018

Products (7)

  • Cisco IOS
  • Cisco 10000 Performance Routing Engine 4 (PRE4)
  • Cisco 10000 Performance Routing Engine 3 (PRE3)
  • Cisco 10000 Performance Routing Engine 2 (PRE2)
  • Cisco 7304 NSE-150 Network Services Engine
  • Cisco 7304 NSE-100 Network Services Engine
  • Cisco 7304 NPE-G100 Network Processing Engine

Known Affected Releases


Description (partial)


PE1 ---- CE1 --------LAN (priority 75, DR)
PE2 ---- CE2 --------LAN (priority 50)

CE1 is DR and PIM assert  winner.
CE1 LAN sub-interface is the forwarding interface.
After shutdown the CE1 LAN main-interface, CE2 become DR as expected, and CE2 LAN sub-interface became forwarding interface.
However, after no shutdown CE1 LAN main-interface, the CE1 outgoing interface is NULL, there is no forwarding interface in this topology.

1# CE1 LAN sub-interface is configured "ip igmp static-group ..."
2# there is no other active receiver in this topology.
3# CE1 & CE2 are the same hardware platform, loaded with the same IOS version. When CE1 & CE2 IOS version are different, we do not see this symptom in test bed.
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Bug Details Include

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