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I just had the very same thought reading the article! "An admin at a local it shop discovered two 3com nics with the same Mac address while setting up a rack o

I just had the very same thought reading the article! "An admin at a local it shop discovered two 3com nics with the same Mac address while setting up a rack of four new servers. The admin got suspicious when reliable network communication was not possible with any of the two servers and after further investigation found the duplicate addresses."

Aeolun 4y ago
This would only be discovered if two nics with the same mac addresses arrive in the same shop at the same time.
tonyarkles 4y ago
I'm not sure if your quote is from personal experience but... and this is totally cliche from the era... I was setting up a Beowulf Cluster made up of salvage 486s in the early 2000s because why not? We were running into some really bizarre issues, and eventually we got down to the just pinging the machines from each other and started discovering that when we went to ping one of them, we would get two replies! Sure enough, two generic NE2K NICs had duplicated MAC addresses!
- mensetmanusman 4y ago
  Beowulf Cluster. I just died and woke up in the 90s
  - tonyarkles 4y ago
    Naturally, it started as a joke. My buddy had a pile of machines that the school board had decided to throw away. Being avid /. fans, I of course said “can you imagine a Beowulf cluster of those?” So then it’s 2am and his basement closet is really warm…
- thaeli 4y ago
  Ha, yeah. I had the same experience, around the same time, also on a Beowulf cluster.
- c0nsumer 4y ago
  I've had this problem in modern times where, when setting up Windows PCs (via WinPE at our enterprise) some NICs would very occasionally not work right with the provided driver and end up with some default MAC. Doesn't work out so well when you have a room full of these PCs all getting imaged at thhe same time and suddenly half a dozen on the same switch have the same MAC. :\ (I believe it came down to a BIOS problem and a new version sorted it out.)
ntac 4y ago
In the late 90s I worked for a company that was afraid of the Internet. They had one computer in a common area that had access to the Internet but not the company's internal network for the ~50 engineers to use. The internal network was coax Ethernet. I was working on a networking project at the time and ran a packet sniffer on the internal network and saw that some MAC addresses could access the outside world. I'm lazy and I didn't like having to go halfway across the building, sit at a slow ass computer to download a datasheet, copy it to a floppy, then walk halfway across the building back to my cube, and finally copy it to my computer. Ain't nobody got time for that. So I modified my network driver to use one of the macaddrs that had internet access. When I needed something from the Internet, I'd load my modified driver then unload it when I was done. Much easier. I thought I was doing it for such short periods of time that nobody works ever notice. Of course I was wrong. After about a month I got called into the IT manager's office. And of course the the macaddr I picked belonged to the VP of engineering who also was the son of the president. Fortunately they understood that young engineers are dumb and do dumb things and let me off with a warning.
- richardfey 4y ago
  On the contrary, I think you did a smart thing.

Aeolun 4y ago

This would only be discovered if two nics with the same mac addresses arrive in the same shop at the same time.

tonyarkles 4y ago

I'm not sure if your quote is from personal experience but... and this is totally cliche from the era... I was setting up a Beowulf Cluster made up of salvage 486s in the early 2000s because why not? We were running into some really bizarre issues, and eventually we got down to the just pinging the machines from each other and started discovering that when we went to ping one of them, we would get two replies! Sure enough, two generic NE2K NICs had duplicated MAC addresses!

mensetmanusman 4y ago
Beowulf Cluster. I just died and woke up in the 90s
- tonyarkles 4y ago
  Naturally, it started as a joke. My buddy had a pile of machines that the school board had decided to throw away. Being avid /. fans, I of course said “can you imagine a Beowulf cluster of those?” So then it’s 2am and his basement closet is really warm…
thaeli 4y ago
Ha, yeah. I had the same experience, around the same time, also on a Beowulf cluster.
c0nsumer 4y ago
I've had this problem in modern times where, when setting up Windows PCs (via WinPE at our enterprise) some NICs would very occasionally not work right with the provided driver and end up with some default MAC. Doesn't work out so well when you have a room full of these PCs all getting imaged at thhe same time and suddenly half a dozen on the same switch have the same MAC. :\ (I believe it came down to a BIOS problem and a new version sorted it out.)

ntac 4y ago

In the late 90s I worked for a company that was afraid of the Internet. They had one computer in a common area that had access to the Internet but not the company's internal network for the ~50 engineers to use. The internal network was coax Ethernet. I was working on a networking project at the time and ran a packet sniffer on the internal network and saw that some MAC addresses could access the outside world. I'm lazy and I didn't like having to go halfway across the building, sit at a slow ass computer to download a datasheet, copy it to a floppy, then walk halfway across the building back to my cube, and finally copy it to my computer. Ain't nobody got time for that. So I modified my network driver to use one of the macaddrs that had internet access. When I needed something from the Internet, I'd load my modified driver then unload it when I was done. Much easier. I thought I was doing it for such short periods of time that nobody works ever notice. Of course I was wrong. After about a month I got called into the IT manager's office. And of course the the macaddr I picked belonged to the VP of engineering who also was the son of the president. Fortunately they understood that young engineers are dumb and do dumb things and let me off with a warning.

richardfey 4y ago
On the contrary, I think you did a smart thing.