Switches--help

Breadfan

My new boss was explaining to me the components in server room and we got to the switches. I know switches (or at least I thought I did) and his explanation is still baffling me.

We use PoE switches (if that makes any difference I dont know, but we have 3 of them and when he was going over that he i asked why he chose an "unmanaged" switch in one of the other buildings across the street; was it because we didnt need to use any vlan capabilties, etc there and he said no, i had switches all wrong...

anyways, he said that even if the switches were linked together not "stacked" that they wouldnt be able to communicate because they each have a different MAC address. I said I thought it was because they would be on totally different VLANS themselves. he said nope

could someone shed some light on what he is trying to tell me? he said if we "stacked" them then the network would see them as one whole device but we dont have it set up that way and in essence, the switches cannot communicate together even if we link them together.

Thanks again. for the help with my DOH moment.....

Mishra

I have a feeling he might be trying to say that they have port-security turned on their switches. So if you were to plug in a unmanaged switch then it would not work until they enabled the MAC address to be able to use the switch port on the managed switches.

Thats my guess.

seuss_ssues

Breadfan wrote:

We use PoE switches (if that makes any difference I dont know

PoE - power over ethernet. It basically allows device that are PoE compatible to use their network link as also their power source rather than also requiring a power adapter and a power outlet.

seuss_ssues

Forgot to mention....to my knowledge a PoE switch does not function any differently than a non PoE switch in terms of switching.

Breadfan

for the clarification

I hope I explained it correctly. I will ask him if we have the port security turned on and that is the reason.

I am also doing alot of reading on PoE since we use VoIP phones here which use it. Interesting stuff indeed

Ahriakin

You need a management interface of some kind to enable port-security also. If you haven't misunderstood what he told you then your boss does not understand switches at all. Stacking is a mechanism whereby some vendors allow multiple managed switches to be connected and Managed as one logical switch (i.e. 4x 24 port 2960s connected using the Stacking ports can all be managed from one session, as if all 4 where part of the same device). But once a switch is directly connected to another (on any port) and the ports are not VLAN restricted or otherwise then you will always have traffic flow between them, that's what they do....

dtlokee

Stacking typically refers to connecting the "fabric" of the switches together as opposed to simply connecting two of the interfaces together that may operate at 1Gb/s. When you stack them you typically will have much higher bandwidth between the switches, and like Ahriakin said they are then managed as one logical switch.

As for using an unmanaged switch at the other site, I guess they were just bing cheap. It will act as one logical network since it does not support VLANs, you can't form a trunk to it, and all traffic that is sent from that switch will end up on the access vlan of the other switch it is connected to on the central site side. I am not entirely sure what he's talkign about.