4.4. Processing Rules
There are several rules that govern processing of ICMP packets. They can be found in RFC 4443 and are summarized as follows:
An ICMPv6 error message must not be sent in the following cases:
Every IPv6 node must implement a rate-limiting function that limits the rate of ICMPv6 messages it sends, and it should be configurable. If this function is implemented properly, it protects against Denial of Service attacks.