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In the early 2000s, I went to a store and bought a Netgear "network hub" either exactly this one, or extremely close to it: https://upload.wikimedia.org/wikipedia/commons/d/d9/4_port_netgear_ethernet_hub.jpg

I can't remember the exact model number or anything, so maybe this one is slightly different. But it looked like that one.

Is it really true that this device was so primitive as to send all data coming into it (from the Internet/cable modem), and any data being sent out from any PC connected to it, to all other nodes/network jacks? Or is that just some misconception that I have had for the last 20+ years?

Something about that sounds insanely wasteful, insecure and just plain illogical. It also seems like it would make a big mess of everything. If my brother surfed the Internet and made a request to example.com, while my PC was also powered on, did that "hub" really send the HTTP packets/data to my computer as well? So I could have sat there and sniffed and spied on anything he did?

If true, how did my computer know what to "reject" and what to handle? It just seems... weird. Was it really such a "major feature" to send packets to the right "node" that they had to make a whole new class of products called "network switch"? It doesn't seem reasonable. It's almost as if a "network hub" was invented in the 15th century or something. I must have got this wrong. Please tell me I have.

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  • (This will likely be closed as off-topic/historical trivia.) Yes, hubs work like that. Yes, it's a Bad Idea(tm) to do so these days. In decades past, in the long-long-ago, it was much cheaper to make a hub, vs. the relative complexity of a switch. Today, the logic to handle dozens of ports is cheaply manufactured and widely available. Also, it should be noted, some late model "hubs" were actually switches. "Hub" at that point what just marketing.
    – Ricky
    May 1 at 3:16
  • @Ricky It seems bizarre to me. So each computer had to figure out if the constant massive stream of data packets was for them or not?
    – A. S.
    May 1 at 4:05
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    If a packet arrives with destination MAC != NIC MAC the packet is dropped by the NIC (unless it's broadcast or multicast MAC)
    – manish ma
    May 1 at 6:01
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Is it really true that this device was so primitive as to send all data coming into it (from the Internet/cable modem), and any data being sent out from any PC connected to it, to all other nodes/network jacks?

Yes. A repeater hub is so simple that it doesn't even have a concept of nodes. It simple copies bits received from the currently active port to all other ports. If a second port becomes active (=receiving bits) the hub signals a collision. Effectively, a hub isn't much more than a "powered wire".

sounds insanely wasteful ...

It is. Regardless the size of the collision domain, the maximum throughput is limited to the single speed of the segment (minus the time wasted on collisions). Imagine a network with 40 nodes and a total throughput of 10 Mbit/s - 97.5% of the cable capacity is wasted.

In the 1980s and early 90s, 10 Mbit/s was considered fast. Mind you, the computers back then couldn't handle larger bandwidths anyway (quite a few choked on 10 Mbit/s).

A switch with 40 Gigabit ports has an (unblocking) ingress + egress capacity of 80 Gbit/s which wasn't even imaginable 30 years ago.

A switch is a much more sophisticated device than a repeater hub. When they were introduced they cost many thousand dollars.

... insecure ...

That depends on your definition of "secure". A wired network without any security features isn't very secure in any modern definition anyway. There is a large number of attack vectors to (switched) networks that need to be mitigated.

... and just plain illogical

No, it's no illogical. Unwanted data is automatically sorted out by each NIC (by dropping frames to other destination addresses than its own one/s), without bothering the host. That hasn't ever changed.

As Ricky has already pointed out, "hub" is somewhat ambiguous as it was used for some time for "switching hubs" as well, before "switch" really caught on.

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