-SYSCTL_NODE(_net_inet, IPPROTO_IP, ip, CTLFLAG_RW, 0, "IP");
-SYSCTL_NODE(_net_inet, IPPROTO_ICMP, icmp, CTLFLAG_RW, 0, "ICMP");
-SYSCTL_NODE(_net_inet, IPPROTO_UDP, udp, CTLFLAG_RW, 0, "UDP");
-SYSCTL_NODE(_net_inet, IPPROTO_TCP, tcp, CTLFLAG_RW, 0, "TCP");
-SYSCTL_NODE(_net_inet, IPPROTO_IGMP, igmp, CTLFLAG_RW, 0, "IGMP");
+SYSCTL_NODE(_net_inet, IPPROTO_IP, ip, CTLFLAG_RW|CTLFLAG_LOCKED, 0, "IP");
+SYSCTL_NODE(_net_inet, IPPROTO_ICMP, icmp, CTLFLAG_RW|CTLFLAG_LOCKED, 0, "ICMP");
+SYSCTL_NODE(_net_inet, IPPROTO_UDP, udp, CTLFLAG_RW|CTLFLAG_LOCKED, 0, "UDP");
+SYSCTL_NODE(_net_inet, IPPROTO_TCP, tcp, CTLFLAG_RW|CTLFLAG_LOCKED, 0, "TCP");
+SYSCTL_NODE(_net_inet, IPPROTO_IGMP, igmp, CTLFLAG_RW|CTLFLAG_LOCKED, 0, "IGMP");