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Cisco Bug: CSCvv57029 - 9400 dual supervisor, unicast packets will not be punted to CPU after a switchover

Last Modified

Sep 06, 2020

Products (1)

  • Cisco Catalyst 9400 Series Switches

Known Affected Releases


Description (partial)

In a 9400 switch with dual supervisors, after a switchover to the standby hot (recently replaced) control plane will break, unicast packets will not be punted to CPU.

Broadcast and multicast are seen in the CPU. This could impact several protocols that communicate using unicast, as example EIGRP will be stuck in Q Count 1. Hello packets will hit the CPU but not unicast so adjacency will not fully come up.

9400 with dual supervisors running 16.9.4, replaced standby supervisor with 16.6.4a, auto upgrade will match the IOS-XE version to 16.9.4 and finally reach SSO.
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