Fortiswitch dropping UDP packets with specific dest port

[datapath-team]

Hi,

We have a Fortiswitch that we're doing multicast streaming through 1 port going out to another port, we receive the packets fine with UDP (dest) port 781 but packets with UDP (dest) port 782 (same source IP & destination IP) are dropped. We can mirror the TX port and see the packets arriving on the port but when mirroring the RX port the packets are not being received on the port. When we add an Ingress ACL to redirect packets with the destination IP specified out to the RX port then we do receive the packets with port 782.

We don't see the same issue with other brands of switch. Does anyone know why a Fortiswitch would be dropping packets with one UDP destination port and not dropping packets with a different UDP destination port if the source IP and dest IP are the same?

Thanks

[Anthony_E]

Hello datapath-team,

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.

Thanks,

[knagaraju]

Hello datapath-team,

We need a remote session to check the packet capture and debugs for the issue.

Regards
Nagaraju.