I currently have 3 hubs daisy-chained together. They are Linksys Etherfast 10/100 AutoSensing 24-pt hubs. Mod#: EFAH24. The middle one is giving me a red blinking light under col which according to the documentation means collisions. This light is blinking continuously. Since my other two are not doing this - i'll assume this is a problem. I have noticed that certain network applications are extremely slow on certain computers. Can I just add a 4th hub and move some of the connections to this hub? Right now the second hub is packed full. How can I test this? MS-DOS promots? I'm not sure what to do here and I'm not sure if this is even the problem with the slow applications. Any help is appreciated.
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Hub getting repeated collisions
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franklin97355
Technical User
Try swapping the hub positions and see if the trouble follows the hub or the position in the network.
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- #3
Throw out the hubs.
Use all switches.
Your instinct was likely to put the heaviest used devices(say, your servers, or your internet access) on the switch. This makes sense. But you still have 48 ports of collision domain asking for attention on the switch for these highly demanded ports.
At least by replacing the hubs with switches you can use the switches capability to:
. store and forward the requests in a less collision prone manner;
. not occupy the attention of the hub connected workstations while this is going on
Use all switches.
Your instinct was likely to put the heaviest used devices(say, your servers, or your internet access) on the switch. This makes sense. But you still have 48 ports of collision domain asking for attention on the switch for these highly demanded ports.
At least by replacing the hubs with switches you can use the switches capability to:
. store and forward the requests in a less collision prone manner;
. not occupy the attention of the hub connected workstations while this is going on
- Thread starter
- #5
If the two hubs are seperate connected to the switch, and all (or most) users are on the hubs, you can have a problem at the switch ports that connects to the hub. Using hubs (one collision domain) it is impossible to prevent collisions, it is inherent to the strucutre of the hub. If you have 20 users on one hub, only one station can transmit at the same time, so only one station is actually using the link to the switch, all others have to wait and fight for their bandwith (This is called CSMA/CD, the mechanisme that controls Half Duplex ethernet). Another disadvantage is that a hub is ALWAYS half duplex.
You can try to fix the speed on the switch ports where the hubs are connected to to 100mB Half Duplex, may by there is an problem with the autosensing.
If you want to do it technically right, you indeed need to change the hubs to a switch. otherwise the hubs will always be the bottleneck.
To tell you, I have seen many customers with these kinds of configurations, replacing the hubs with switches and configuring them right (speed, duplex settings and sometimes by using VLAN's) it almost always solved the problems they had.
Regards,
Robert
Robert Wullems
Network Specialist
SCP/SCE/SCM/CNX/MCP/MCSA/Network+
***************************************
If you can Sniff it, you can solve it!
***************************************
You can try to fix the speed on the switch ports where the hubs are connected to to 100mB Half Duplex, may by there is an problem with the autosensing.
If you want to do it technically right, you indeed need to change the hubs to a switch. otherwise the hubs will always be the bottleneck.
To tell you, I have seen many customers with these kinds of configurations, replacing the hubs with switches and configuring them right (speed, duplex settings and sometimes by using VLAN's) it almost always solved the problems they had.
Regards,
Robert
Robert Wullems
Network Specialist
SCP/SCE/SCM/CNX/MCP/MCSA/Network+
***************************************
If you can Sniff it, you can solve it!
***************************************
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