Wireshark · Wireshark-dev: Re: [Wireshark-dev] Patch to packet-eth.c to clarify address ig/lg bits

[Guy Harris <guy@xxxxxxxxxxxx>]

ronnie sahlberg wrote:

> Only dissect the LG bit if it is a unicast address (i think this makes sense)

I think there are both locally-administered and globally-administered 
group addresses.  IEEE 802-2001 says:

	A 48-bit universal address consists of two parts. The first 24 bits 
correspond to the OUI as assigned by the IEEE, except that the assignee 
may set the LSB of the first octet to 1 for group addresses or set it to 
0 for individual addresses. The second part, comprising the remaining 24 
bits, is administered by the assignee. In the 48-bit LAN MAC address, an 
example of which is shown in Figure 8, the OUI is contained in octets 0, 
1, 2, and the value assigned by the assignee is contained in octets 3, 
4, 5. This address, including its OUI, is used throughout this document 
as the basis for examples of LAN MAC addresses and protocol identifiers.