IGMP issue with Arista switches?

Hi there,

I'm currently having a strange network issue which is possibly related to IGMP and I'm kindly asking for some input :-)

We've several Arista switches from the 7050 product line, in this case it's an MLAG of two DCS-7050S-52-R. The setup is as simple as possible:

We've two DCS-7050S-52-R mlag'ed together and a few servers which are connected via LACP to this MLAG stack. Those LACP channels are configured as trunk with 2 VLANs.

We've been deploying new servers during the past days and can see a lot of traffic (around 50-200 Mbps) on the port channels without even having the servers in production. We then used tcpdump to capture the traffic and could see that the new servers can see traffic (TCP based, not only multicast) from other servers connected to the same MLAG stack.

The switches are running EOS 4.18 and "sh igmp snooping vlan 100" shows the following:

Global IGMP Snooping configuration: ------------------------------------------- IGMP snooping : Enabled IGMPv2 immediate leave : Enabled Robustness variable : 2 Report flooding : Disabled Vlan 100 : ---------- IGMP snooping : Enabled IGMPv2 immediate leave : Default Multicast router learning mode : pim-dvmrp IGMP max group limit : No limit set Recent attempt to exceed limit : No Report flooding : Disabled IGMP snooping pruning active : False Flooding traffic to VLAN : True 

For me, the interesting part here is "Flooding traffic to VLAN: True". I've compared this with another Arista MLAG running EOS 4.19 where this is set to "False". IGMP settings are on default on both MLAGs. It seems like Arista changed the default value from 4.18 to 4.19. We don't have those issues on the other MLAG running 4.19.

Am I right that this could be the reason for this behaviour? If not, do you have any other ideas?

Thanks in advance!