Gigabit hubs -- do they exist? (or was I halucinating)

[x88x]

Yes, yes, I know this is a really weird request, but hey...

Basically, I have a situation at work such that I have need of a hub (yes, a hub, not a switch or router; a hub), but I also need high throughput. Now, I distinctly remember seeing a D-Link device a few years back that at least was labeled as a Gigabit Hub, but I have been searching on and off for a few months now and can't find anything.

So, has anybody seen such a thing? Even better, does anyone know where I can buy one?

[Luke122]

I'm not sure that I've ever seen a Gigabit "HUB" specifically.. what do you need it for, that a switch will not function?

[x88x]

We need at least one port to be able to see all traffic across the device. We have a Cisco switch that should be able to do it, but it's too smart for its own good and keeps messing with the rest of the network, and we need to be able to just plug it in and go without any custom configuration for the network it's sitting on.

[Kayin]

Yes, they exist-just a dumb switch with no higher functions, right? Gimme a few hours, it's been a long time since I did any work with higher-end stuff.

Although my network is partially Cat6A now...

[x88x]

No, dumb (layer 2) switches operate much more efficiently than hubs, which is why they're all over the place. Switches know what (physical) ports on the device traffic is going to, and only sends the traffic to that port. Hubs use a common pipe, so all traffic is sent to all devices connected to it. If anyone makes a layer 2 switch with a spanning port, that would work too, but not just a normal layer 2 switch.

EDIT:
hub (http://en.wikipedia.org/wiki/Network_hub)
switch (http://en.wikipedia.org/wiki/Network_switch)

Actually, looking at that, I guess a hub is actually a layer 1 switch.

[Airbozo]

An unmanaged switch will work for what you need. Most unmanaged switches do not direct any traffic or interfere with the network in any way except to balance traffic across all ports.

At least that is what we use our unmanaged switches for. Works just like a hub except better throughput.

[x88x]

Do you have a product line with a spanning port? Because all the unmanaged switches I've seen are just normal level 2 switches.

[mtekk]

An unmanaged switch will work for what you need. Most unmanaged switches do not direct any traffic or interfere with the network in any way except to balance traffic across all ports.

At least that is what we use our unmanaged switches for. Works just like a hub except better throughput.

Uh, no. For a switch to be a switch it must operate as a multiport bridge (use MAC address "routing") otherwise they are Hubs and they are being mislabeled (x88x has is right). Hubs are just a multi port repeater. I have never seen a hub faster than 10/100 (probably due to the requirements for gigabit).

When you say it keeps messing with the rest of the network, what do you mean?

[x88x]

TBH I don't remember exactly what it was doing; I think it was trying to integrate into the spanning tree environment, which in turn was interfering with how the existing network equipment was functioning. Whatever we find, it needs to be able to immediately sit down on any network with no configuration and mirror all the ports on it to at least one of the ports. 10/100 would definitely be better than the 10T hub we ended up picking for use in that one instance, so if you know of any 10/100 hubs, that would help. I was just hoping to find something with gigabit that would work for what we need. I'm almost to the point of just grabbing one of the little desktops we have lying around, throwing two gigabit NICs in it, and putting it inline between a switch and the network as a bridge.

[mtekk]

May I ask why you need to monitor all of the traffic on the network?

As for 10/100 hubs, I have a 5 port linksys one sitting on the shelf, but I can't find the power brick.

Performance wise, as long as the computer isn't really slow, bridging through two gigabit ports will probably be faster than using a 10/100 hub.

[x88x]

We don't need all the traffic on the entire network, just all the traffic going to and from the systems on the one device. I think I'll just try doing a bridge to a switch; probably cheaper to buy 2 gigabit NICs than a network device that would do what we need anyways. :P

[Airbozo]

Uh, no. For a switch to be a switch it must operate as a multiport bridge (use MAC address "routing") otherwise they are Hubs and they are being mislabeled (x88x has is right). Hubs are just a multi port repeater. I have never seen a hub faster than 10/100 (probably due to the requirements for gigabit).

When you say it keeps messing with the rest of the network, what do you mean?

Hmm, then it was explained to me incorrectly by several different network guru's. I am not a network guy by any stretch so I could have misunderstood them. Network switches are sold as managed and unmanaged with the managed ones being way more expensive.

Now I have more reading to do... lol

[x88x]

Hmm, then it was explained to me incorrectly by several different network guru's.

Not entirely surprising; no offense to your gurus, it's just that it is a very commonly misunderstood thing these days. Basically, a hub sends all traffic that it sees to all ports. Because of this, any device on a hub can see all traffic to and from all other devices on that hub. However, as a result of this, the available bandwidth is divided among the devices on the hub (ie, if there are 5 devices on a 10/100Mbps, each only gets 20Mbps bandwidth) and there is a danger of packet collisions. Because of all three of these reasons, 99% of the time, switches are much preferable.

Because hubs operate on level 1 of the OSI model (http://en.wikipedia.org/wiki/OSI_model), they only know about the electrical impulses coming over the wire, and just spit those electrical impulses out everywhere that they can, hoping that they get where they're supposed to. Switches on the other hand, operate on level 2 (or sometimes level 3 in the case of managed switches), so they can read the packet headers and see what IP address the packets are supposed to go to. Using the ARP data available to them, the can use that to find out the MAC address of the device that the packet is supposed to go to. Since it is operating on level 2, it knows which devices have which MAC addresses, so it can send the packets only to the desired location. Like I said, 99% of the time, this is exactly what you want from a switch, but every now and then.....

mtekk, I just realized that in my previous post I forgot to answer your question; basically, the reason that I need to monitor the traffic on these systems is that we need to have a record of all the traffic that went to and from these systems over a certain period of time.