What is the ICMPv6 type for Neighbor Solicitation (NS) messages?

Neighbor Solicitation (NS) messages are part of the Internet Control Message Protocol for IPv6 (ICMPv6) and are used primarily to discover other nodes on the same local link and to determine their link-layer addresses. This is critical for the functionality of the Neighbor Discovery Protocol, which allows nodes to communicate their presence on the network and helps manage the local address resolution process.

The correct type code for Neighbor Solicitation messages is indeed 135. This value is defined in the ICMPv6 specification. In the broader context of ICMPv6 message types, it is beneficial to note the roles of the neighboring message types. For instance, the type code 133 is designated for Neighbor Solicitation, while 134 is used for Router Advertisement, and 136 is for Redirect message types.

Understanding the specific purpose and type codes of these messages is crucial for network troubleshooting and management in IPv6 environments, as NS messages play a vital role in the link-layer address resolution process necessary for device communication.