Each PixLite 16 Mk2 is set up to control 96 universes of pixels. They are both operating on the same network, along with the sending software. In the example shown below, two PixLite 16 Mk2 controllers are being used to drive a large LED screen. If a network is not designed and configured properly, it could result in dropped packets and/or unstable connections. If the display consists of many controllers, with many universes of data, this can be a significant task for the network to achieve.

It sounds like we did a good job constraining our multicast traffic but we still have one problem.In a pixel light display, the network needs to transport large amounts of data from the sending software to the pixel controllers at high speeds.

When the switch detects a multicast enabled router then it will add the corresponding entry in the CAM table.įrom now on, all multicast traffic that has destination MAC address 0100.5e01.0101 will only be forwarded on interface Gi0/1, Gi0/4 and the internal interface to the CPU. Once IGMP snooping is enabled, the switch will detect multicast enabled routers and it does so by listening to the following messages:IGMP General Query (0100.5e00.0001)OSPF (0100.5e00.00.5e00.0006)PIM version 1 and HSRP (0100.5e00.0006)PIM version 2 (0100.5e00.000d)DVMRP (0100.5e00.0004) Why did the switch add the interface of the router in the CAM table? The interfaces that were added are for H1, R1 and the internal interface. In the CAM table above you can see an entry for MAC address 0100.5e01.0101 which corresponds with multicast group 239.1.1.1. To answer these questions we’ll have to take a closer look at IGMP snooping. How do we deal with the video server that never joins any multicast groups but only streams traffic to it? What do we do when we use IGMP version 1? Our hosts will not send any leave group messages so there’s nothing to snoop. This sounds simple but there is more to this story. As the name implies, this is done by listening to IGMP traffic between the router and hosts:When the host sends a membership report for a multicast group then the switch adds an entry in the CAM table for the interface that is connected to the host.When the host sends a leave group for a multicast group then the switch removes an entry in the CAM table for the interface that is connected to the host. IGMP snooping allows us to constrain our multicast traffic. All hosts will receive our traffic whether they want it or not. Since this MAC address has never been used as a source, all multicast traffic will be flooded. When the switch receives this traffic then it will do a lookup for MAC address 0100.5e01.0101. Above we have a video server that is streaming multicast traffic to destination 239.1.1.1, the destination MAC address will be 0100.5e01.0101.

Igmp snooping la gi