Many NIC's can spoof MAC. Almost all routers can. And yes, you are correct, you can get a MAC address collision. Only 48 bits. But if I remember correctly, the 48 bits gets cut into pieces. The manufacturer piece is 24 bits, so a maker has 24 bits for their devices which is big, but not that big. But as you say, the odds of a collision on a specific LAN are very small. The odds of a duplicate having been produced though are quite high.
Unless, of course, you work in a manufacturer's lab.
Routers and switches are an entirely different proposition.
Years ago our datacenter manager once ordered some network controlled rack power strips. You were able to power cycle outlets and monitor power use per socket in order to balance load or monitor usage
He tested one and ran into odd problems when he tried to network more of them.
After calling support he learned that all of the devices ship with a default MAC address and you need to assign a MAC address to each device.
Took alot of hair pulling before he got to the realization that someone could ship devices having the same MAC address.
He tested one and ran into odd problems when he tried to network more of them.
After calling support he learned that all of the devices ship with a default MAC address and you need to assign a MAC address to each device.
Took alot of hair pulling before he got to the realization that someone could ship devices having the same MAC address.
Long ago, 8088 and NetWare days, Novell even gave you a driver which would spoof the MAC. In the rush from $300 3Com to the $10 bottom, some copycat net-cards had the same MAC number on ALL cards. They worked fine individually, how they got past prototype testing, but two or more on one LAN was a bust. So the BAT file to load the driver had to be hand-crafted to over-ride the MACs with a unique number on every PC.
Here the police and allied agencies use the IMEI and SIM combination for tracing location, our country is more than 90% on cell phones, the proportion of fixed line users is small.
And thanks to construction and diggers, most offices also have wireless internet, at least as back up.
Now, fiber optic to home is being introduced.
I had an old HP motherboard, the BIOS had a MAC address which could not be changed.
And thanks to construction and diggers, most offices also have wireless internet, at least as back up.
Now, fiber optic to home is being introduced.
I had an old HP motherboard, the BIOS had a MAC address which could not be changed.
Yep. Apple launched the M1 in November of 2020 ... two years ago! It's received rave reviews and is supposedly umpteen times faster than the Intel CPU it replaced across a variety of CPU intensive tasks. It also consumes considerably less power resulting in 20 hours of battery life for a 13" MacBook Pro laptop (vs about 8 hours for the Intel version).
There's an ARM version of Windoze as well: https://learn.microsoft.com/en-us/windows/arm/overview
Tom
I just remember reading the article saying Apple would be back to using Intel CPUs in no time. Looking like that will not be the case.
ARM only provides the cores, MMU, DMA and bus archictectures... plus some glue.
The design of the chip would be (a) custom by Apple or (b) custom by ARM Holdings designed for Apple.
The "fab" proper is taped out, most likely to Taiwan or someplace like that.
What amazes me about Apple is how myopic and/or arrogant they are about their naming convention.
There has been for quite a long time an ARM Cortex-M series of cores. I've programmed the M0 and M1. Plus the Rs and As.
Before that was IOS, which was the longtime Cisco Internetworking OS, since 90s. I programmed that too... I don't understand how Apple was able to get away with it... all I can think is that they had to pay Cisco LOTS of money.
Windoze on ARM? They likely forced the PCI and a Little Endian architecture just to make life miserable. I miss the old PPC. Big Endian makes a lot more sense... if you deal with ARM and AXI you are in hog heaven... but then you grab that god da!!n Intel with a PCI and I go through reams of blank paper taking notes and byte swapping to figure out the data. It's a real killer when the IDE does the byte swapping when you dump memory but then when you move to a JTAG you see the raw data.
0xDEADBEEF becomes 0xEFBEADDE.. I think.
I'm currently running ARM on Linux and vxWorks. No byte swapping in sight.
Plus great pipelining.
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TSMC, I think, makes the ARM CPUs for Apple.
Part of the reason they invested in CPU fabrication (fine lines), in addition to their older stuff like modem and sound chips.
They also work a lot with fabless chip makers like VIA.
Never heard of an Apple fab as in a chip making facility owned by Apple.
Part of the reason they invested in CPU fabrication (fine lines), in addition to their older stuff like modem and sound chips.
They also work a lot with fabless chip makers like VIA.
Never heard of an Apple fab as in a chip making facility owned by Apple.
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You don't make an ARM CPU chip.
ARM cores are built into SoCs (System On a Chip) which achieve very high levels of integration. Stuff like the cores, the MMU, AXI, AHB, APB, etc... are all sold by ARM Holdings as models that developers build into their SoC. The ARM IP is delivered as HDL for inclusion into different FPGAs and emulators. Once the developers are happy, they process the model and tape it out to the Fab where it becomes silicone.
I am not aware of anyone "buying" an ARM core chip.
This is very different from Intel which sells hardware, not IP.
This is also the reason why ARM is doing so well in the SoC world. There is no way an Intel CPU can hope to achieve the combination of functionality, lower power, performance and functional adaptation of an ARM based SoC.
for many mobile systems, well, since it so happened that Android is popular, you only mentioned it
I don't design the hardware, just smoke it with too much firmware.
Some of those SoCs are loaded with cores... the SoCs in smart phones are astounding in their complexity. Then you got hard/SSD drives. Memory management, DMA, bus matrices, multimedia, modems, flash, etc... We're talking about some truly serious hardware processing into chips that are smaller than an Intel core.
It's been a while since I programmed a router/switch, but even then they were moving directly to custom designs with built in hardware acceleration (exactly what the ARM M cores are meant for).
I only program Big Brains, and yes, I too love ARM stuff. ;-)
ARM sells building blocks for chips, and is a purely knowledge based company, they do not sell you a chip as Intel does.
And you have yourself informed us that the ARM cores are found in many devices.
Android is a Linux based OS, which itself descended from UNIX, is it not?
That free software was to make your desktop look like an Android phone or tablet, now more people use those compared to desktops in many countries...
And see the specs...multiple cores, cameras front and back, fast internet, pocket size, portable, plenty of memory...who needs a PC now?
And you have yourself informed us that the ARM cores are found in many devices.
Android is a Linux based OS, which itself descended from UNIX, is it not?
That free software was to make your desktop look like an Android phone or tablet, now more people use those compared to desktops in many countries...
And see the specs...multiple cores, cameras front and back, fast internet, pocket size, portable, plenty of memory...who needs a PC now?
I use a couple of Android tablets running Tidal into DACs into two of my stereos. They are exceptional as media servers, and with 512GB SD card they come out to less than $250 at Costco.
My only concern with Android is the truly rotten, IMHO, user interface. In this, I find the classic Linux presentation managers and Windoze far superior.
However, I find the mobile world to be too limited for most of my home needs. Why can't they make a tablet with TWO USB-C connectors... one for power and one for OTG? Would it be so expensive? When I travel for more than a few days I take my tablet for reading my email, which I can hot-spot into my cell phone. And how about someone made a control board for a tablet? The thing will slide off my hands and my sliding fingers will do things....
Camera... OK, I take lots of pictures, but a good camera is eons better, but just more cumbersome to take around. How about building a camera that has an USB that can be controlled by a cell phone?
And do not even start with the abomination that is Android Auto. I can write volumes.
I guess my issue with Android is the developers... cheap software outsourced by cheap MBAs to a certain subcontinent with no thought of quality.
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I never knew that India is an Android development hub.
I have a friend, architect, uses an iPad as camera, and presentation device. 10" screen.
And you can actually connect many devices over wi-fi and Bluetooth without connectors. No need for many USB sockets.
Bear in mind that ARM is essentially a RISC unit, good for dedicated controllers as in HDD, not as good as Wndoze in user interface.
Android is a little basic in comparison, but does 90$ of the work for most people. Like banking, travel tickets, and so on.
And also, the variety of software in M$ is much more, in office, accounting, graphics and so on.
Android is free, I think, so Google makes money on it through some other way.
Never met a bean counter who was generous about budgets...
I have a friend, architect, uses an iPad as camera, and presentation device. 10" screen.
And you can actually connect many devices over wi-fi and Bluetooth without connectors. No need for many USB sockets.
Bear in mind that ARM is essentially a RISC unit, good for dedicated controllers as in HDD, not as good as Wndoze in user interface.
Android is a little basic in comparison, but does 90$ of the work for most people. Like banking, travel tickets, and so on.
And also, the variety of software in M$ is much more, in office, accounting, graphics and so on.
Android is free, I think, so Google makes money on it through some other way.
Never met a bean counter who was generous about budgets...