ICMP Redirect Linux Kernel Settings

ICMP Redirects You can check the current setting like so: $ sysctl net.ipv4.conf.default.accept_redirects net.ipv4.conf.default.accept_redirects = 1 $ sysctl net.ipv4.conf.default.secure_redirects net.ipv4.conf.default.secure_redirects = 1 $ sysctl net.ipv4.conf.default.shared_media net.ipv4.conf.default.shared_media = 1 $ sysctl net.ipv6.conf.default.accept_redirects net.ipv6.conf.default.accept_redirects = 1 The accept_redirects setting enables acceptance of ICMP redirects. The secure_redirects setting, if enabled, ensures only redirects from a default gateway are accepted (if accept_redirects is itself enabled). The shared_media setting informs the kernel whether the physical network connected to the a network interface is a shared medium, or not.