vc pode fazer assim tb
coloca isto aki na inicialização
echo 16384 > /proc/sys/net/ipv4/neigh/default/gc_thresh1
echo 32768 > /proc/sys/net/ipv4/neigh/default/gc_thresh2
echo 65535 > /proc/sys/net/ipv4/neigh/default/gc_thresh3
echo 90 > /proc/sys/net/ipv4/neigh/default/gc_interval