48 port switch with port identification by IP address

BlizzardX · 20 Jul 2016 at 21:58

Hi

I'm putting this question here as I suspect the tech is more related to enterprise than home use.

I've got a comprehensive home server setup (3 machines running as VMhosts, 1 as a storage host and the other as live TV and server essentials). As a result of VM migration and bringing at least four network ports from each room in my house, I'm in need of either another 24 port 1gbe switch or 48 if compelling enough.

What I do want is Vlan routing and IP address identification on each port; e.g. so I can find out if I've forgotten to record the machine to port I can figure it out as my cabinet is quite out of the way and more awkward to get to from the back.

I suspect for Vlan routing I can use a layer 3 / 3 lite (or 2+ as some call it) but what would I need for IP address identification if this is possible? I'm assuming a full fat Layer 3 switch would be required and that the 2+/3 lite versions won't owrk?

So, if the above makes sense... What sort of switch should I be looking at? Anyone know of any makes/models/versions that would satisfy me? I'm obviously looking at used enterprise/SMB class units here from Ebay etc. as I can't afford new prices...

Any help is really appreciated.

As a side note, my current switch is a 1gbe 24 port Linksys SRW2024.

Hellsmk2 · 23 Jul 2016 at 04:16

You could probably pick up an old Cisco 3560, which should satisfy requirements. Depending on budget, you could try and pick up a 3750x, but in all honesty, that's overkill for a home setup.

Both support CDP, so figuring out what is connected would be simple enough. However, just adding a description to each port as you configure it would also suffice.

BlizzardX · 23 Jul 2016 at 04:43

Thanks, had a look and these are Fast Ethernet aren't they, not 1GbE?

ov_sjo · 23 Jul 2016 at 06:44

Pretty much most managed switches will let you look at the ARP table to identify what's on each port.

What do you mean by VLAN routing? VLANs are layer 2.

BlizzardX · 23 Jul 2016 at 06:47

Most as in Layer 3, or will those classed as Layer 2+ or Layer 3 lite do?

Vlans won't route across unless you have a some form of routing to do so, Layer 3 switches from what I understand (and it is limited, I don't do this for a living) can do the layer 2 Vlan and then allow you to route across the vlans so they can see each other if you want them to.

ov_sjo · 23 Jul 2016 at 06:51

You need to think of the two layers separately. Routing is done at layer 3, so IP. A layer 3 switch has some level of routing functions in it. It's irrelevant if VLANs are being used or not.

What is it exactly you're trying to do?

Have you considered creating VLAN trunks to a separate router/firewall device? Or even a trunk to your VM hosts and run a software firewall in a guest?

Caged · 23 Jul 2016 at 18:13

As far as I know IP address per-port on a switch isn't really possible as if you wanted to do that you'd effectively be turning a switch into a router with lots of interfaces and absolutely tank performance. What you can do is get the MAC address table from the switch and then cross-reference it with an ARP table from a layer three device (and this could be the same switch with an L3 interface on each VLAN.

As mentioned, LLDP and CDP run from the clients will also tell you what switch and port they are connected to.

WILD9 · 1 Aug 2016 at 10:49

Hey BlizzardX, I think in terms of routing the feature you are looking for is inter-VLAN routing rather than vlan routing, you want to be able to route traffic between VLANs based on access controls?

https://networklessons.com/switching/intervlan-routing/

It's a layer 3 feature but some layer 2(ish) switches will give you enough layer 3 functionality to setup static routes between VLANs an example being the Cisco 2960G.

In terms of IP address to port, thats not really a traditional feature of managed switching but as Caged says, MAC Address to port is and with the MAC address you can get the IP from ARP tables.