for i in `seq 0 70`; do ip link del dummy$i; done; for i in `seq 0 70`; do ip link add type dummy; done; for i in `seq 0 70`; do ipset add qwe 0.0.0.0/0,dummy$i; done; Reveals the problem. Only 64 records can be added, but there are no obvious restrictions on that. I s it possible to increase the limit ? -- Segmentation fault