Enabling this option allows a “global” bound socket to work across L3 master domains (e.g., VRFs) with packets capable of being received regardless of the L3 domain in which they originated. Only valid when the kernel was compiled with CONFIG_NET_L3_MASTER_DEV.
udp_mem - vector of 3 INTEGERs: min, pressure, max Number of pages allowed for queueing by all UDP sockets.
min: Below this number of pages UDP is not bothered about its memory appetite. When amount of memory allocated by UDP exceeds this number, UDP starts to moderate memory usage.
pressure: This value was introduced to follow format of tcp_mem.
max: Number of pages allowed for queueing by all UDP sockets.
Default is calculated at boot time from amount of available memory.source