Cisco Support Community
Community Member

SG300 Multicast Setup and Options

I'm using Windows Server 2012 R2 WDS to deploy an install image using multicast. I have a single host connected to a SG300-10 and 6 client machines connected to the switch as well. So far this is what I've done.

  • Enabled "Bridge Multicast Filtering" set set it to "MAC Group Address" for both IPv4 and IPv6
  • Enabled IGMP Snooping
  • Enabled IGMP Querier for IGMPv3
  • Enabled Immediate Leave for Querier
  • The switch is running in Layer 2 mode

However, after setting all this up, my multicast is working but very slow. I understand this is a common issue with multicast. I verified that I'm getting a large number of NACK responses (10-30 per second). I've tried multicasting a single client and it seems to work fine. I did find the transfer speed to cap out at around 200mb/s even though i'm using an SSD and a gigabit ethernet adapter. But I wasn't getting any NACK responses. Once I add more clients though, the NACKs are bad and my speed drops from 200mb/s to less than 90mb/s.

At this point I don't know what's causing that and what I can do to help fix it. Here are some questions I have.

  1. Are there performance differences between IPv4 multicast and IPv6 multicast?
  2. What is the difference between Forwarding Method being set to MAC Group Address and IP Group Address
  3. Do I need to specifically set a Multicast Router Port?
  4. Does having my router in Layer 2 vs Layer 3 mode make a difference in my multicast performance?


Firmware Version:

Boot Version:

Language Version

Everyone's tags (3)
CreatePlease to create content