What Is MAC AddressĪs the MAC (Media Access Control) address is linked to the hardware of the network adapters, they are also known as the “hardware address” or “physical address”. On This Page :īefore learning the difference between MAC address and IP address, you should get an overview of them. MAC address vs IP address: which to pick? If you also wonder that, read this post now! Here, MiniTool introduces the two addresses respectively and then compares them from several aspects. More specifically, being able to tell the hardware address of a device from its IP address is a convenience for administrators, but this same information is available to everyone else as well.Both MAC address and IP address are used to identify a machine on the Internet. This represents a form of information sharing that can be problematic in our modern world of hackers and trackers. However, it violates one of the tenets of layer design, which is that an address in one layer (the hardware address) should not be tied to the addresses at another (the IP address). Linking hardware device addresses to IP addresses offers practical benefits, as explained above. One important facet of this is that “detail hiding” using layers also enhances security and privacy. One of the fundamentals of network design is the use of layers, which allow different technologies to interoperate while hiding unnecessary details that would cause complications in the implementation of each technology. To understand the issue here, it’s necessary to first have a small digression into network design philosophy. The bigger concerns with EUI-64 are those old bugbears that administrators know too well: privacy and security. In practice, this is a relatively minor consideration most of the time because hardware doesn’t change that often-this is something that typically occurs in the scope of years, not hours or days. One disadvantage of EUI-64 is that tying the hardware address to the IP address means that if the hardware address changes, the IP address needs to change as well. Using EUI-64 makes this simpler because seeing the IP address of a device indicates immediately what the MAC address is and vice versa. Troubleshooting: When troubleshooting devices, administrators must often switch back and forth between working with IP addresses and hardware addresses.Address harmonization: Administrators no longer must keep track of two separate, unrelated addresses for each device.Support for autoconfiguration: It is easy to generate an appropriate globally routable local address from any hardware device using its hardware address and a process such as SLAAC.More specifically, having device hardware addresses and IPv6 addresses directly linked provides value in the following areas: The benefits of EUI-64 generally relate to practical considerations: simplicity and administrative efficiency. Once again, if you do the math, you can see that if you apply the EUI-64 process to the 2001:ABCD:1234:5678::/64 prefix along with the MAC address of the particular interface, the result is the IPv6 address shown above. The resulting IPv6 global unicast address has become: Note that the link-local address that we previously manually assigned appears in the output of the IPv6 information of this interface. Take a look at this series of commands and their results. On a Cisco IOS device, as soon as you enable the IPv6 capability on an interface, the device will automatically generate a link-local address using the EUI-64 process by default. Link-local addresses are of the form FE80::/10. Link-local addresses, as the name suggests, have only local significance, so they are never routed. Remember that the link-local IPv6 address is an IPv6 address that is automatically generated and assigned to an active IPv6 interface. The first scenario involves generating a link-local IPv6 address on the interface of a Cisco router. We’ll examine two particular cases that we often see on Cisco IOS devices. Let’s take a look at how EUI-64 actually operates on a real device. Real-world example of EUI-64 configuration It is used to differentiate individual devices or interfaces within the same network or subnet. The interface identifier created via the EUI-64 process serves as the device-unique portion of the address. This address can then be used by a device to access both local networks and the global Internet.The network prefix and interface identifier are concatenated to make the final (global unicast) IPv6 address.EUI-64 is used to map the MAC address into a 64-bit EUI-64 interface identifier.The MAC address comes from the hardware device.The leftmost 64 bits of the address come from the network prefix, which defines the network portion of the address. Now that we have seen how EUI-64 mapping works, let’s pause for a bit of a recap and see how the various pieces fit together in IPv6:
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |