1  {
 2    boot.kernel.sysctl = {
 3      "net.ipv4.conf.all.rp_filter" = 1;
 4      "net.ipv4.conf.default.rp_filter" = 1;
 5      "net.ipv4.conf.all.accept_source_route" = 0;
 6      "net.ipv4.conf.default.accept_source_route" = 0;
 7      "net.ipv4.conf.all.accept_redirects" = 0;
 8      "net.ipv4.conf.default.accept_redirects" = 0;
 9      "net.ipv4.conf.all.secure_redirects" = 0;
10      "net.ipv4.conf.default.secure_redirects" = 0;
11      "net.ipv4.icmp_echo_ignore_broadcasts" = 1;
12      "net.ipv4.icmp_ignore_bogus_error_responses" = 1;
13      "net.ipv4.conf.all.send_redirects" = 0;
14      "net.ipv4.conf.default.send_redirects" = 0;
15      "net.ipv6.conf.all.accept_redirects" = 0;
16      "net.ipv6.conf.default.accept_redirects" = 0;
17      "kernel.sysrq" = 0;
18      "kernel.core_uses_pid" = 1;
19    };
20  }