This tutorial will give participants a structured approach to tracking down and fixing interdomain multicast problems. The talk will break the troubleshooting process down into four main stages:

1. Gathering necessary information
2. Verifying that the local receiving network knows of an active receiver
3. Checking for network knowledge of an active source (local to the source, then interdomain via MSDP)
4. Tracking the forwarding state from the receiver back towards the source.

Examples/case studies will be given, and screen shots from Juniper and Cisco routers will be included. There will be pointers to Best Common Practices, reference materials, and tools.

This is an intermediate-to-advanced talk; participants should have a basic knowledge of the protocols (IGMP, PIM, MBGP, MSDP) and terminology (RP, DR, (S,G), (*,G), RPF, SPT, etc.) and be supporting multicast in their network. Participation in previous NANOG tutorials "Introduction to IP Multicast Practice" (May 2001) or "Deploying IP Multicast (Feb 2002)" would also be helpful.

PDF presentation