Switching from Layer 2 Hub to Layer 2 Switch

[BU-Terrier]

Question guys -

I'm having a hard time trying to figuring out the implications of switching a layer 2 hub with a layer 2 switch.

Basically I was presented a question about the implications of moving from a Wired 100 Mbps Layer 2 Switch to a 100 Mbps Layer 2 hub.

A few questions:

• How would throughput be affected? Would it be slower? I said the throughput would be faster due to the fact that hubs broadcast traffic all the time and there would be a performance hit on the network.
  
• How would frame collisions be affected? Wouldn't this lessen the amount of frame collisions?
  
• How would Frame loss be affected? I can't envision any frame loss..
  
• How would LAN security be affected? Wouldn't switches make it easier to secure the data?
  
• How would future growth and speed upgrades be affected?

Your help would be greatly appreciated!

 

[Red Squirrel]

Do they even make 100mbps hubs? I don't see a reason why one would want to do this. A hub will not perform as well because everything will be on the same collision domain. Basically only two devices will be able to talk to each other at a time and the rest will have to wait. The more devices the worse it gets.

As far as security, with hubs it's also much easier for any machine on it to sniff ALL data.

 

[imagoon]

Question guys -

I'm having a hard time trying to figuring out the implications of switching a layer 2 hub with a layer 2 switch.

Basically I was presented a question about the implications of moving from a Wired 100 Mbps Layer 2 Switch to a 100 Mbps Layer 2 hub.

A few questions:

• How would throughput be affected? Would it be slower? I said the throughput would be faster due to the fact that hubs broadcast traffic all the time and there would be a performance hit on the network.
  
• How would frame collisions be affected? Wouldn't this lessen the amount of frame collisions?
  
• How would Frame loss be affected? I can't envision any frame loss..
  
• How would LAN security be affected? Wouldn't switches make it easier to secure the data?
  
• How would future growth and speed upgrades be affected?

Your help would be greatly appreciated!

1)With 2 devices, hub vs Switch = nearly identical. Collisions reduce the performance but that is a fairly low count with 2 devices. As device count goes up, hub performance would suffer, high collisions and with one large data domain. Switches reduce the collision domain to none (well technically switch + device but that isn't an issue.) Switches also only forward packets (baring the flood packets for MAC identification) to the port they are meant to go to. So a 100Mbps hub has to split the 100Mbps between all devices. Switches can channelize. Port 1 talking to 2 at 100Mbps will not prevent port 3 and 4 talking to each other at 100Mbps.

2) Switches reduce frame collisions to zero.

3) Collisions = loss. Switches only lose frames (generally) when the line is overloaded and the frames need to be discarded.

4) Switches are much easier to secure. Hubs broadcast everything to anyone. Switches can often be configured for port authentication, mac limits, vlans etc.

5) Hub technology is not longer supported on 10Gbps networks should be the first indication that switching is here to stay and Hub tech is dead. Hub like tech is alive and well in wireless though.

 

[imagoon]

Do they even make 100mbps hubs?

They used to.

 

[smitbret]

It's the 11th commandment:

Thou shalt replace all hubs with switches as soon as the hub is discovered.

 

[azazel1024]

Question guys -

I'm having a hard time trying to figuring out the implications of switching a layer 2 hub with a layer 2 switch.

Basically I was presented a question about the implications of moving from a Wired 100 Mbps Layer 2 Switch to a 100 Mbps Layer 2 hub.

A few questions:

• How would throughput be affected? Would it be slower? I said the throughput would be faster due to the fact that hubs broadcast traffic all the time and there would be a performance hit on the network.
  
• How would frame collisions be affected? Wouldn't this lessen the amount of frame collisions?
  
• How would Frame loss be affected? I can't envision any frame loss..
  
• How would LAN security be affected? Wouldn't switches make it easier to secure the data?
  
• How would future growth and speed upgrades be affected?

Your help would be greatly appreciated!

Sounds like a school/paper/test question.

But, see everyone's answers as they've effectively replied.