Managed switches

[BatchFile]

after failing to find what's causing an intermittent problem on the network, having checked server logs, wiresharked them and restarted everything, I think it's time to look at some new switches (as the Netgears we've got are 10 years old).

 

I've just started to look at my first chouice supplier for this kind of thing, and I've hit a question:

What's the difference between a Layer 2 switch and a Layer 3 switch? I thought that was more to do with how you plugged the network together - but it seems the hardware's different judging by this: Managed Switches | Network Switches | Active Networking | Shop By Type | Videk | Network Systems and IT Solutions

 

Can someone enlighten me please?!

[3s-gtech]

Layer 3 = network layer = packet forwarding and routing. In other words, L3 is useful if you'll be doing routing traffic between networks on the device.

[BatchFile]

like setting up VLANs for BYOD and stuff you mean? if so that's what I'll need.

[Mr.Ben]

Yup that's it -

 

You can create VLANs on layer 2 switches, but they don't apply any intelligence when forwarding packets (the VLAN's won't be able to talk to each other). They can't route packets based on IP address or prioritise packets.

 

At a minimum you'll need a layer 3 switch at the top of every cab you have, but I would get L3 across the board now.

 

You can have layer 2 switches connected to untagged VLAN ports, and the layer 3 switch does the routing etc.

Edited January 29, 2014 by Mr.Ben

[3s-gtech]

Not for setting VLANs up as such, but routing between them (if you put them on different ranges so requiring routing). VLAN support should be fully functional on a modern L2 switch.

[ataylor]

We recently installed BYOD on our network and most of our switches are only L2 and some of them are getting pretty old!

[SkreeM1980]

The switch(s) that does the routing between the VLAN's needs to be L3, the others are fine at L2, but if you want things like VOIP vlan that will need priority get L3.

 

My favourites are HP Procurve (anything with a 2 at the start of the model number)

[m25man]

How did you wireshark them?

 

I often read here on Edugeek of the use of wireshark for all problems invisible to the naked eye but unless taken from a tap or monitor port the most your likely to see is your own traffic and a few broadcasts.

 

In most cases your probably better off looking at your gateway traffic for clues.

 

Replacing all your switches won't help you if you have a network configuration issue, what tends to happen is you stumble across the real cause of the problem as you rip and replace or at worse after you have swapped everything out and it's still the same you actually then revisit the real cause....

 

Yes they may all be 10 years old but it sounds like they have been reliable for the last 9.x of them?

[seawolf]

after failing to find what's causing an intermittent problem on the network, having checked server logs, wiresharked them and restarted everything, I think it's time to look at some new switches (as the Netgears we've got are 10 years old).

 

I've just started to look at my first chouice supplier for this kind of thing, and I've hit a question:

What's the difference between a Layer 2 switch and a Layer 3 switch? I thought that was more to do with how you plugged the network together - but it seems the hardware's different judging by this: Managed Switches | Network Switches | Active Networking | Shop By Type | Videk | Network Systems and IT Solutions

 

Can someone enlighten me please?!

 

After 10 years it's probably a good idea to start looking at new switches as I would imagine most if not all of them are 100M? There could be another issue going on, but at 10 years old it's a good reason to refresh and alo look at your network topology to see if you can improve it. Do you have a flat network BTW? It may be your network has simply hit the limit. Using VLANs properly will minimise excess broadcast traffic around the network.

 

I second the Hp ProCurves. You will need a 1Gb layer 3 switch to function as a router and core switch, and 1Gb Layer 2 switches elsewhere. PoE and 10GbE for your network backbone (uplinks between switches) are worth considering as well if you have a long refresh cycle. A couple of good combinations using the HPs would be the 5406zl for core/routing and 2520g for endpoint; or, if you have more to spend and want 10GbE go for the 8206zl with 2910s for endpoint.