Initial triage: eos_multicast_base lab validation failures (never tested before)

[dhalperi]

Problem

The eos_multicast_base lab exhibits validation failures when comparing Batfish route predictions against actual device operational data in a multicast routing environment with Arista EOS devices using PIM SSM and IGMP.

Technical Details

This lab implements PIM SSM (Source-Specific Multicast) operation with static RPs and IGMP version 3 across Arista EOS devices. The validation failures indicate discrepancies between Batfish modeling and actual device behavior for main RIB routes on multicast-enabled devices.

Observed In

eos_multicast_base

Symptoms

• Main RIB route validation failures on 3 Arista EOS devices (rp1, rp2, rcvr)
• Route matching issues between device operational data and Batfish predictions
• Specific failures include OSPF route discrepancies with different protocol classifications (ospfInterArea vs OSPF)
• Route metric and next-hop validation mismatches in multicast topology

Configuration Patterns

• PIM SSM multicast routing topology with 3 Arista EOS devices (rp1, rp2, rcvr)
• 2 IOS test harness devices (fake_rcvr1, fake_rcvr2) for IGMP group simulation
• IGMP version 3 configuration for multicast group management
• Static RP configuration for PIM operation
• OSPF as underlying unicast routing protocol

Next Steps

Investigation needed into Batfish multicast routing modeling, particularly:

• OSPF route classification consistency (ospfInterArea vs OSPF protocol naming)
• Route metric calculation in multicast-enabled topologies
• PIM SSM and IGMP interaction effects on routing table validation
• Arista EOS specific multicast routing behavior modeling