# Reverse path filtering - drop packets with spoofed source IPs
net.ipv4.conf.all.rp_filter = 1
net.ipv4.conf.default.rp_filter = 1

# Don't send ICMP redirects (not a router)
net.ipv4.conf.all.send_redirects = 0
net.ipv4.conf.default.send_redirects = 0

# Don't accept ICMP redirects
net.ipv4.conf.all.accept_redirects = 0
net.ipv4.conf.default.accept_redirects = 0
net.ipv6.conf.all.accept_redirects = 0
net.ipv6.conf.default.accept_redirects = 0

# Don't accept source-routed packets
net.ipv4.conf.all.accept_source_route = 0
net.ipv4.conf.default.accept_source_route = 0

# Log martian packets (spoofed, source-routed, redirect)
net.ipv4.conf.all.log_martians = 1
net.ipv4.conf.default.log_martians = 1