[    2.621192] ip (276) used greatest stack depth: 12336 bytes left
[  328.601998] ip (4087) used greatest stack depth: 12320 bytes left
[ 1173.175204] blackhole_netdev_xmit(): Dropping skb.
[ 1173.175284] blackhole_netdev_xmit(): Dropping skb.
[ 1173.175321] blackhole_netdev_xmit(): Dropping skb.
[ 1173.175359] blackhole_netdev_xmit(): Dropping skb.