Multicast running PIM

[hizuto]

I am traying to test multicas for a prouect using VLC. I have enable ping with igmp v3, configured a static RP, created multicast polices and regular policies and it's not working.

I decided to test from the Fortigate to the other aide of the network to see where was the problem. I started testing then on the same switch that has the vlan thru FortiLink and it does work.

Enabled another port on the Fortigate with a different submet and created the needed policies and it does not work.

I tried disabling multicast-forward with no luck, I also increased the TTL to 100 in the VLC.

I see the source transmitting the video in the captures and I also see the potential receiving requesting the appropriate group thru the 224.0.0.22, he is requesting the group that is transmitting the video but the Forti does not forward the video. This does not make sense to me, they are both connected on the same Fortigate

[Jean-Philippe_P]

Hello hizuto, 

Thank you for using the Community Forum. I will seek to get you an answer or help. We will reply to this thread with an update as soon as possible. 

[Jean-Philippe_P]

Hello,

We are still looking for an answer to your question.

We will come back to you ASAP.

[Jean-Philippe_P]

Hello again hizuto,

I found this solution. Can you tell us if it helps, please?

To troubleshoot the multicast issue you're experiencing, follow these steps:

1. Verify Multicast Forwarding Configuration: Ensure that multicast forwarding is enabled on the FortiGate. In NAT mode, use the following command:

   
   

   config system settings
     set multicast-forward enable
   end
   

2. Check Multicast Policies: Confirm that you have configured the necessary multicast policies to allow the multicast traffic through the FortiGate. Without these policies, the traffic will not be forwarded.
   
   

3. Review TTL Settings: Since you have increased the TTL to 100 in VLC, ensure that the multicast-ttl-notchange option is not enabled, as it prevents the TTL from being changed. If needed, disable it:
   
   

   config system settings
     set multicast-ttl-notchange disable
   end
   

4. Interface and VLAN Configuration: Verify that the interfaces and VLANs are correctly configured to handle multicast traffic. Ensure that the interfaces are not set to enhanced MAC VLAN, as multicast forwarding is not supported on these interfaces.
   
   

5. Check for Policy Conflicts: Ensure there are no conflicting policies that might be blocking the multicast traffic. Review both multicast and regular policies for any discrepancies.
   
   

6. Test with Different Subnets: Since you mentioned testing with a different subnet, ensure that the policies and routing are correctly set up for this subnet. Double-check the configuration for any missing or incorrect settings.
   
   

7. Capture and Analyze Traffic: Use packet captures to analyze the traffic flow and identify where the packets are being dropped. This can help pinpoint the issue.

If the problem persists after these checks, consider reaching out to Fortinet support for further assistance.