Internet Core Protocols: The Definitive Guide

Parameter Problem error messages

The Parameter Problem error message generally means that something is wrong with the IP datagram itself, and that the datagram is being discarded.

Parameter Problem errors almost always result from an incorrect usage of an IP option. For example, a device may have sent an IP datagram with a malformed Source Route option in the IP header. This datagram would fail to be delivered due to this error, and would get discarded by the recipient (or an intermediary gateway) once the error was detected. Although it might seem that a Destination Unreachable: Source Route Failed error message would be sent in this case, that would not be true since the problem was a malformed option, rather than an undeliverable address.

In order to provide more-detailed reporting, the Parameter Problem message provides three different submessages (using the ICMP Message Code field as described later in Section 5.2.1.1). The submessages offered by Parameter Problem include:

Pointer Indicates the Error

This error means that there is a specific problem with the datagram’s structure (such as a malformed header field). The location of the bad data is provided in the ICMP Message Data field of the Parameter Problem error message, allowing the sender to determine the cause of the failure.

Required Option Is Missing

This error means that a required IP option has not been defined. This message is used only with the Security options, which are used only by the U.S. military, and are therefore ...