Small Inexpensive Programmable Network Hub/Switch

I am looking for an inexpensive small 4 or more port programmable network hub/switch.

Currentlly I am using a Netgear (10BaseT) 4 port hub.  This works fine except it does not do exactly what I want it too.

What I need the switch/hub to do is simple.  The uplink port will be connected to a backbone.  When ever a packet of any type comes in this port I want it to go out all the other ports.  When a packet comes in any OTHER port I want it ONLY sent out the uplink port.

In other words, the ports are only allowed to talk too and listen too packets on the uplink port.

Please help!

Who is Participating?
jwalsh88Connect With a Mentor Commented:
you could setup up a router using linux but I would not suggest it.  Now you have a server full of hardware to look after.  Unless you get a brand new PC with excellent support you could be looking at lots of nights troubleshooting why your network doesn't work.  If you do get a new PC, even a cheap one will cost a few hundred dollars and dont forget about the 4 port ethernet card.  Thats going to cost you atleast 200 dollars for a cheap one that will probably only last a couple years if your lucky.  A good one will cost more then the switch.  I would go with the managed Cisco Catalyst 1548 8 port switch.  I am sure you can find it for under $800 and it will be the most reliable and highest performing piece of hardware you own.  Also, even the basic support is very good compared to that of small companies like D-Link and Linksys.

But if you want to go cheap get an old slow computer and you can use something like or to setup a router using linux small enough to run from a ramdisk and boot from a floppy.

That was ofcourse svindler's suggestion I was just kind of throwing those links in so you get a better idea.  I would definitely not load full blown linux on a computer to do this since the reliability of hard drives is so much lower then that of RAM Memory.  using the linux router project you wont have any need for a hard drive.
Well, if you buy a switch with a MAC table larger than the total number of nodes on your network, it will forward your packets to the proper place. So packets bound for the backbone from a client PC won't get spewed to another client. But it does not prevent a PC to talk to another PC. For that, you would need a router + access list or firewall.

Secondly, you won't find any small, inexpensive managed switches. I doubt in fact you will find any switch that you can program to do this.

You could do this on any VLAN capable switch.  setup every port except the uplink port on their own VLAN then setup the uplink port to be part of all VLANs.  There is a limit to this though.  But since you are currently using a 4 port hub I don't think this will be a problem.
Cloud Class® Course: C++ 11 Fundamentals

This course will introduce you to C++ 11 and teach you about syntax fundamentals.

I guess I would have to ask why you want to do this anyway? What is the goal, perhaps there is a better way.

You could implement this using a linux pc with a four port ethernet card. This would be less expensive than a trunk capable switch, and more customisable, too, provided you don't need high bandwidth.
I was thinking on the lines of using bridging with linux, not routing. As I understand the question, Matthew wants to do something on the lines of private vlans in Cisco terminology. That does NOT come cheap. I haven't seen any inexpensive switches that was able to do something similar.

If the 1548 can do this, I would like to know.

Svindler, he wants one uplink port to be able to forward traffic it recieves on it's port to all other ports.  then it wants all other ports to only forward traffic to the one uplink port.  This can be done simply by using normal VLANs.

uplink port belongs to VLAN1, VLAN2, VLAN3
port 2 belongs to VLAN1
port 3 belongs to VLAN2
port 4 belongs to VLAN3

If I am wrong on that let me know.  And the 1548 can do that.
jwalsh, how would traffic from the backbone be propagated to all vlans on the switch?
After reading your question I fail to see why a simple Linsys router with four 10/100 switched ports would'nt do what you want.

If you want to bar users on the four ports from communication with each other, that might be a problem. But, you will have four switched ports, they can communicate with the uplink port independently of each other, and the users can talk to each other without the uplink port getting any clue that they are.

If you want to isolate all users from each other and stop them from any communication from each other, then you are talking about a more expensive device.

             Joe Massimino
I forgot about this question.  You can make one port part of multiple or all vlans on a cisco 1548M Micro Switch.

See below:
I see that the 1548M is much more capable than I thought. It looks like it could solve most of the requirements, unless matthew REALLY wants all traffic entering from the backbone propagated on all ports, even if it is not broad- or multicast.
Cisco does caution though, about only connecting it to a host; not another switch or hub. This could probably be solved by tweaking the stp parameters.

This question appears to be abandoned. I will allow one week before I close this question
with the following recommendation:

- points to jwalsh88

if there is any objection to this recommendation then please post it here within 7 days.


EE Cleanup Volunteer
per recommendation

Community Support Moderator @Experts Exchange
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

All Courses

From novice to tech pro — start learning today.