# Multicast

Den här artikeln är skriven enligt att advanced routing är aktiverat.

## Skillnader legacy routing / advanced routing

I ett långt supportärende om SSM fick vi till slut följande information av PA TAC:

*After Analyzing the Pcaps we can see the packets are coming with any source.*   
*Since we are using Dynamic IGMP, source IP must be included in the Packet for Firewall to Process further so that it's FIB can be populated*

*For Static IGMP, we are specifying Source in Firewall configuration itself so that if IGMP packets come from that particular source will be allowed*  
*While Dynamic IGMP has an option to add Filters, those are basically like access list which either allows or denies the traffic but it will not be enforced as Source*

*Why it is working on Legacy Routing but not Adv. Routing?*   
*==> Legacy routing is relaxed compared to Adv. Routing which is much more strict and in compliance with RFC.*

M.a.o., IGMPv3 Membership Reports behöver en source IP och kan inte använda sig av ASM. Advanced routing generellt följer tydligen RFCerna bättre.

## IGMP

### IGMP Static Join

Konfigurerar man ett static join värde under Logical Router -> LR-namn -> Multicast -> IGMP -> Static så skickas automatiskt ett PIM Join-meddelande uppströms. I konfigurationen behövs ett namn, ett interface med en lyssnare (mot receiver), en grupp-adress och en source-adress. Source-adressen måste vara en /32.

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