mindaugas@517713:~$ strace ipset create cloudflare_ipv4 hash:net 
execve("/sbin/ipset", ["ipset", "create", "cloudflare_ipv4", "hash:net"], [/* 16 vars */]) = 0
brk(0)                                  = 0x7fbc927a7000
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fbc92184000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=24237, ...}) = 0
mmap(NULL, 24237, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7fbc9217e000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/lib/x86_64-linux-gnu/libipset.so.3", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\220\322\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0644, st_size=177056, ...}) = 0
mmap(NULL, 2272440, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7fbc91d39000
mprotect(0x7fbc91d5c000, 2093056, PROT_NONE) = 0
mmap(0x7fbc91f5b000, 36864, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x22000) = 0x7fbc91f5b000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P \2\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=1840928, ...}) = 0
mmap(NULL, 3949248, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7fbc91974000
mprotect(0x7fbc91b2e000, 2097152, PROT_NONE) = 0
mmap(0x7fbc91d2e000, 24576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x1ba000) = 0x7fbc91d2e000
mmap(0x7fbc91d34000, 17088, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7fbc91d34000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/usr/lib/x86_64-linux-gnu/libmnl.so.0", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0@\31\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0644, st_size=18424, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fbc9217d000
mmap(NULL, 2113552, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7fbc9176f000
mprotect(0x7fbc91773000, 2093056, PROT_NONE) = 0
mmap(0x7fbc91972000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x3000) = 0x7fbc91972000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/lib/x86_64-linux-gnu/libdl.so.2", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\320\16\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0644, st_size=14664, ...}) = 0
mmap(NULL, 2109744, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7fbc9156b000
mprotect(0x7fbc9156e000, 2093056, PROT_NONE) = 0
mmap(0x7fbc9176d000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x2000) = 0x7fbc9176d000
close(3)                                = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fbc9217c000
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fbc9217a000
arch_prctl(ARCH_SET_FS, 0x7fbc9217a740) = 0
mprotect(0x7fbc91d2e000, 16384, PROT_READ) = 0
mprotect(0x7fbc9176d000, 4096, PROT_READ) = 0
mprotect(0x7fbc91972000, 4096, PROT_READ) = 0
mprotect(0x7fbc91f5b000, 24576, PROT_READ) = 0
mprotect(0x7fbc9238e000, 4096, PROT_READ) = 0
mprotect(0x7fbc92186000, 4096, PROT_READ) = 0
munmap(0x7fbc9217e000, 24237)           = 0
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/ipset", O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
brk(0)                                  = 0x7fbc927a7000
brk(0x7fbc927cb000)                     = 0x7fbc927cb000
socket(PF_NETLINK, SOCK_RAW, 12)        = -1 EPROTONOSUPPORT (Protocol not supported)
write(2, "ipset v6.20.1: ", 15ipset v6.20.1: )         = 15
write(2, "Cannot open session to kernel.\n", 31Cannot open session to kernel.
) = 31
exit_group(1)                           = ?
+++ exited with 1 +++