Difference between Unicast local address (ULA) and Mesh-Local EID (ML-EID)

[rodruizronald]

Hi,

I have a question about how IPv6 addressing works in an OpenThread network. I read in the OpenThread website that the ML-EID is also known a Unique Local Address (ULA). So, it seems like they are the same in terms of scope. Is there any difference between them? 

https://openthread.io/guides/thread-primer/ipv6-addressing

ULA: fd11:22:0:0:ccf0:a5d5:3b90:6da2

ML-EID: fdde:ad00:beef:0:d7b4:3e5e.6315:d513

[AndreasF]

Hi.

ULA stands for Unique Local Address, it is an IPv6 address that is guaranteed to be unique for a device in a specified scope. For example, an ML-EID is a ULA for the mesh-local scope. ML-EID stands for Mesh-Local Endpoint Identifier. An Endpoint Identifier that is unique to that device in a Thread interface, regardless of network topology.  Thread Network uses a specific category of ULAs for the purposes of mesh routing and management within the network. In the context of the Thread Network, these are called MLAs (Mesh Local Addresses)–either ML-EID (Mesh-Local Endpoint Identifier) or ML-RLOC (Mesh-Local Routing Locator)–and are identified by a ULA prefix referred to as the MLP (Mesh Local Prefix).

Best regards,

Andreas

[rodruizronald]

Thank you Andreas.