Network Related Kernel Runtime Parameters for Hosts and Routers

$ sudo sysctl -w net.ipv4.conf.all.accept_local=0

net.ipv4.conf.all.accept_local = 0

$ sudo sysctl -w net.ipv4.conf.all.accept_redirects=0

net.ipv4.conf.all.accept_redirects = 0

$ sudo sysctl -w net.ipv4.conf.all.accept_source_route=0

net.ipv4.conf.all.accept_source_route = 0

$ sudo sysctl -w net.ipv4.conf.all.arp_filter=

net.ipv4.conf.all.arp_filter = 

$ sudo sysctl -w net.ipv4.conf.all.arp_ignore=

net.ipv4.conf.all.arp_ignore = 

$ sudo sysctl -w net.ipv4.conf.all.drop_gratuitous_arp=1

net.ipv4.conf.all.drop_gratuitous_arp = 1

$ sudo sysctl -w net.ipv4.conf.all.log_martians=1

net.ipv4.conf.all.log_martians = 1

$ sudo sysctl -w net.ipv4.conf.all.route_localnet=0

net.ipv4.conf.all.route_localnet = 0

$ sudo sysctl -w net.ipv4.conf.all.rp_filter=1

net.ipv4.conf.all.rp_filter = 1

$ sudo sysctl -w net.ipv4.conf.all.secure_redirects=0

net.ipv4.conf.all.secure_redirects = 0

$ sudo sysctl -w net.ipv4.conf.all.shared_media=

net.ipv4.conf.all.shared_media = 

$ sudo sysctl -w net.ipv4.conf.default.accept_redirects=0

net.ipv4.conf.default.accept_redirects = 0

$ sudo sysctl -w net.ipv4.conf.default.accept_source_route=0

net.ipv4.conf.default.accept_source_route = 0

$ sudo sysctl -w net.ipv4.conf.default.log_martians=1

net.ipv4.conf.default.log_martians = 1

$ sudo sysctl -w net.ipv4.conf.default.rp_filter=1

net.ipv4.conf.default.rp_filter = 1

$ sudo sysctl -w net.ipv4.conf.default.secure_redirects=0

net.ipv4.conf.default.secure_redirects = 0

$ sudo sysctl -w net.ipv4.conf.default.shared_media=

net.ipv4.conf.default.shared_media = 

$ sudo sysctl -w net.ipv4.icmp_echo_ignore_broadcasts=1

net.ipv4.icmp_echo_ignore_broadcasts = 1

$ sudo sysctl -w net.ipv4.icmp_ignore_bogus_error_responses=1

net.ipv4.icmp_ignore_bogus_error_responses = 1

$ sudo sysctl -w net.ipv4.ip_local_port_range=32768 65535

net.ipv4.ip_local_port_range = 32768 65535

net.ipv4.tcp_invalid_ratelimit = 

# sysctl --system

$ sudo sysctl -w net.ipv4.tcp_rfc1337=1

net.ipv4.tcp_rfc1337 = 1

$ sudo sysctl -w net.ipv4.tcp_syncookies=1

net.ipv4.tcp_syncookies = 1

$ sudo sysctl -w net.ipv4.conf.all.forwarding=0

net.ipv4.conf.all.forwarding = 0