CONFIG_UML_NET_MCAST is not available for thedefaultarchitecture x86.
Result is shown for architecture um
Multicast transport (obsolete)
modulename: umcast.ko
configname: CONFIG_UML_NET_MCAST
Linux Kernel Configuration
└─>UML Network Devices
└─>Multicast transport (obsolete)
In linux kernel since version 2.6.12
This Multicast User-Mode Linux network transport allows multiple
UMLs (even ones running on different host machines!) to talk to
each other over a virtual ethernet network. However, it requires
at least one UML with one of the other transports to act as a
bridge if any of them need to be able to talk to their hosts or any
other IP machines.
To use this, your host kernel(s) must support IP Multicasting.
For more information, see
<http://user-mode-linux.sourceforge.net/old/networking.html> That site
has examples of the UML command line to use to enable Multicast
networking, and notes about the security of this approach.
NOTE: THIS TRANSPORT IS DEPRECATED AND WILL BE REMOVED SOON!!! Please
migrate to UML_NET_VECTOR.
If unsure, say N.
UMLs (even ones running on different host machines!) to talk to
each other over a virtual ethernet network. However, it requires
at least one UML with one of the other transports to act as a
bridge if any of them need to be able to talk to their hosts or any
other IP machines.
To use this, your host kernel(s) must support IP Multicasting.
For more information, see
<http://user-mode-linux.sourceforge.net/old/networking.html> That site
has examples of the UML command line to use to enable Multicast
networking, and notes about the security of this approach.
NOTE: THIS TRANSPORT IS DEPRECATED AND WILL BE REMOVED SOON!!! Please
migrate to UML_NET_VECTOR.
If unsure, say N.