[    1.962693] ip (242) used greatest stack depth: 12384 bytes left
[    2.551022] ip (276) used greatest stack depth: 12368 bytes left
[    2.595626] ip (280) used greatest stack depth: 12352 bytes left
[   22.187323] ip (2215) used greatest stack depth: 12200 bytes left
[ 1168.201425] blackhole_netdev_xmit(): Dropping skb.
[ 1168.201498] blackhole_netdev_xmit(): Dropping skb.
[ 1168.201544] blackhole_netdev_xmit(): Dropping skb.
[ 1168.201583] blackhole_netdev_xmit(): Dropping skb.