Troubleshooting Multicast packets to CPU

Overview This article covers different scenarios where undesirable multicast traffic can be punted to CPU.   Topology   Scenarios 1. Unsolicited traffic When the switch receives multicast traffic, there are two main checks made: 1.Is the source locally connected (i.e. is the source IP of the traffic in the same subnet as the IIF) OR 2. Is there a valid mroute state for the S,G If neither or the above apply, the multicast data traffic will be punted to CPU and no mroute state will be created. Note: Neither of the above checks apply in code versions prior to 4.14.x for...
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MLAG ISSU

Overview MLAG ISSU (In-Service Software Upgrade) upgrades EOS software on one MLAG peer with minimal traffic disruptions on active MLAG interfaces and without changing the network topology. Note: Traffic impact could be seen for orphan links, active partial links and packets in flight   MLAG considerations before upgrade   I. Check for configuration inconsistencies Following features should be configured consistently on each switch: VLANs Switchport configuration on port channel interfaces that are configured with an MLAG ID STP configuration (global) In EOS versions 4.15.2F onwards, we can use MLAG configuration check feature: https://eos.arista.com/eos-4-15-2f/mlag-config-check/   II. Resolve ISSU warnings Resolve the...
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