- Lockdown mode disables all direct root access to ESXi host.
- It disable SSH access to ESXi host.
- Also user will not be able login through vsphere client.
- By default, local user does not exist on the ESXi host.
- So before enabling Lockdown mode, make sure that, local user (non-root) has created on the ESXi host.
Ethernet was implemented by Group called DIX ( Digital, Intel and Xerox).
- It Uses Media Access Control address (MAC) burned on every ethernet card
- It is 48 bits (6 bytes) written in Hexadecimal Format
- Higher 24 bits are OUI (Organizationally Unique Identifier) and it is assigned by IEEE to each vendor. And it is unique among all the vendors
- High-order bit(47th bit) of OUI is the Individual/Group (I/G) bit. When it is 0, we can assume that address is the MAC address. When it is 1, we can assume it is broadcast or multicast address in Ethernet.
- Next bit of OUI (46th bit) is the Global/Local bit (G/L) also known as (U/I). When it is 0, it represent Globally administered address (as per IEEE) and when it is 1 it represent locally governed and administered address.
- The low-order 24 bits are vendor assigned bit. This portion commonly start with 00:00:00 for the first ethernet card and continues till FF:FF:FF for the last ethernet card (total cards : 1,67,77,216)
Ethernet Addressing shown Below.