Multicast is working within a site but not working between sites

[csdinesh18]

When we try to ping multicast group IP 239.1.2.3, we're getting reply from the receiver within the site. 

But, when the receiver is on a different site, only first ping is working. From the next packet, it's not working.

What is the reason for this?

[Georg Pauwen]

Hello,

post a schematic drawing of the setup that does not work, showing how everything is connected, as well as the full running configurations of the devices involved.

[csdinesh18]

Denver site and Chicago sites are connected via Cisco SDWAN
- Denver WAN Edge router (10.10.10.145, DEN-EDGE-CSR) will be the default gateway for RP (10.10.10.146) & sender (10.10.10.147). It also acts as a replicator. They’re all in the same LAN
- Chicago WAN edge router (10.20.10.145, CHI-EDGE-CSR) is the default gateway for the receiver (10.20.10.146). They’re in the same LAN

Sender IP: 10.10.10.147
Receiver IP: 10.20.10.146
RP IP:10.10.10.146

When we skipped SDWAN and form GRE tunnels between the sites also, we noticed the same issue.

[balaji.bandi]

You may need MSDP i guess here, but would be nice some config and network picture illustrate how your setup done.

[csdinesh18]

Denver site and Chicago sites are connected via Cisco SDWAN
- Denver WAN Edge router (10.10.10.145, DEN-EDGE-CSR) will be the default gateway for RP (10.10.10.146) & sender (10.10.10.147). It also acts as a replicator. They’re all in the same LAN
- Chicago WAN edge router (10.20.10.145, CHI-EDGE-CSR) is the default gateway for the receiver (10.20.10.146). They’re in the same LAN

Sender IP: 10.10.10.147
Receiver IP: 10.20.10.146
RP IP: 10.10.10.146

When we skipped SDWAN and form GRE tunnels between the sites also, we noticed the same issue.