Do NOT send ICMP if no neighbour


Linux Kernel Configuration
└─>Networking support
└─>Networking options
└─>Do NOT send ICMP if no neighbour
In linux kernel since version 2.6.12  
Normally, an "ICMP host unreachable" message is sent if a neighbour
cannot be reached because there is no VC to it in the kernel's
ATMARP table. This may cause problems when ATMARP table entries are
briefly removed during revalidation. If you say Y here, packets to
such neighbours are silently discarded instead.