Dell OS 9 won't successfully peer with a bgp router with IPv4 multicast routing capability

I've tried peering a Dell OS 9.11.2.2 bgp process with a cumulus quagga bgpd, both set to be routing IPv4 anycast and multicast routes.

What happened was Dell OS 9.11.2.2 stopping the establishment process sending a notification of "OPEN message error - unknown" right after receiving a KEEPALIVE from the cumulus quagga. (they work well when the cumulus quagga has been set not to route IPv4 multicast)

Could anybody know how to debug this problem?

Here is the pcap capture file captured on the cumulus quagga ubuntu host in which you can check the failed peering process from the beginning of OPEN messages : https://drive.google.com/uc?export=download&id=0B1xRHpWM_gd4MkxSODdNbjNuclU

Best Regards,

Gunwoo Gim