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Cisco Bug: CSCus48657 - Typ/Thawk ucode: source mac transition between bundle member NPs broken

Last Modified

Jul 30, 2018

Products (1)

  • Cisco ASR 9000 Series Aggregation Services Routers

Known Affected Releases

5.3.0.BASE 5.3.2.BASE

Description (partial)

Symptom:
L2 bridging traffic may hit two known unicast flooding problems:
1.  After a bundle member goes down, MAC address learned on the bundle member may be lost on some NPs. Those NP may flood the known unicast MAC traffic for up to 2.5 minutes. 

2. Traffic flooding for up to 2.5 minutes when one of the PW ECMP path goes down.

Conditions:
The event to set the base condition for flooding is an NP which learns MACs from wire for bundle AC/PW/PW-HE/PBB-eVPN service has deleted all member interfaces of a bundle or all ECMP paths for a VPLS-PW/PBB-eVPN/PW-HE. This event happens before the learned MAC addresses age out.

The traffic flood can occur in following 2 scenarios: 
1. ASR9k has over 1M learned MAC address in steady state,  intermittent known unicast traffic flooding can occur.
2. Known unicast flooding can occur right after Asr9k experienced a MAC flush due to Topology Change Notification in multi-homing topology, or MAC withdraw notification on LDP signaled PW.
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Bug Details Include

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