ICMP redirects

ICMP redirects are a feature of the Internet Control Message Protocol (ICMP), specifically ICMP Router Advertisement and ICMP Redirect messages. These messages are used by routers to inform hosts about a better route for sending packets to a specific destination. When a router detects that a host is sending packets on an inefficient path, it can send an ICMP Redirect message to inform the host of a more direct route to the destination.

The main purpose of ICMP redirects is to optimize network traffic and improve the efficiency of routing, especially in scenarios where a host is sending packets through an unnecessary router when a more direct route exists.

However, there are security concerns associated with ICMP redirects. Attackers can potentially manipulate these messages to redirect traffic to their malicious routers, leading to traffic interception or various forms of man-in-the-middle attacks. As a result, some security-conscious organizations or administrators may choose to disable ICMP redirects as a precautionary measure.

Whether you should disable ICMP redirects depends on your specific network configuration and security requirements. In many cases, it might be safe to leave ICMP redirects enabled, especially within trusted and well-configured networks. However, if you have a specific security concern or if you’re operating in a high-security environment, disabling ICMP redirects could be part of your overall security strategy.

If you’re uncertain about whether to disable ICMP redirects or not, it is recommended to consult with your network security team or a qualified network administrator who can assess your network setup and make an informed decision based on your specific requirements.