Feature: Multicast Deploy Across Multiple Subnets/VLANs

[leo150250]

Currently, FOG requires specifying a single network interface for multicast operations. This works fine in a flat network, but in environments with multiple subnets or VLANs (e.g., VLANs 10, 40, and 80), this becomes a limitation. For example, if I want to perform a multicast deployment only on computers in VLAN 80, I need to manually adjust the FOG settings to use the correct interface before starting the multicast.

Proposed Idea: Introduce the ability to register subnets within FOG and associate them with specific network interfaces. This way:

• Groups of hosts could be linked to a subnet (e.g., Group X belongs to VLAN 80).
• When initiating a multicast task for that group, FOG would automatically select the appropriate network interface based on the subnet configuration.
• If no specific interface is configured for that subnet/group, FOG would fall back to the global multicast interface setting.

This approach would eliminate the need for manual configuration changes before each multicast operation and make deployments across segmented networks much more efficient.

I know there is a Subnet plugin, but it doesn’t seem to address multicast behavior (I apologize if it has and I didn't saw that option on it!). Extending this concept to include multicast interface mapping would be a great improvement for environments with multiple VLANs.

[George1422]

While I understand your proposed idea and commenting on that is up to the developers.

Multicast imaging is a strange beast. It's success depends on your infrastructure's design more than FOG. For successful multicast imaging (you may be able to do that today) your network switch infrastructure needs to have igmp snooping enabled. Multicasting uses network multicasts which are typically blocked by your core router. Much like DHCP you need to enable a proxy service on your core router to forward multicast packets between the subnets. DHCP has a dhcp-relay or dhcp-helper service to forward dhcp packets from remote subnets and sends them toward your main dhcp server. For multicasts your core router needs to have a service like igmp proxy to listen for multicasts and then forward them towards the main network. If you have this multicast helper or igmp proxy configured you can multicast using your existing FOG setup.