i have the following case :
i have a managed switch and want to use it monitor a cctv camera .. and there is an unmanaged switch between the camera and the managed switch..
my Q is : can i monitor and detect any thing wrong happens beyond the unmanaged switch .. for example if something wrong happens with the camera can i see it?
I presume, that an Unmanaged switch is like an hub/repeater.
when the devices that is behind the unmanaged switches goes wrong, does it send out a message (like snmp traps) etc., if so, then the hub / repeater can relay the information to the switch and based on that we can take corrective measures.
As for as the link connectivity is concerned , the switch will report connectivity problem only with its immediate device. although the cctv being unmanaged switch goes off, since the link b/w the switch and the unmanaged switch is still alive it might not say the problem with the cctv unless CCTV would explicitly send back any messages .
I will let the experts to pour some more thoughts but this is just my 2 cents.
the "only" thing that differs from a managed switch and an unmanaged switch is that with the first you have a more controlled scenario (please pass me this differentiation ). This means that with a managed switches you can, for example, create Vlans, manage single ports, query the switch, etc...
I think that in your scenario there shouldn't be problems to monitor the cameras.
The only problems that you can occur is if the switches doesn't support the "Jumbo frames" (frames bigger than 1500bytes of payload). If not, you the unmanaged switch will drop these frames.
Do you have an idea of what kind of traffic the cameras will generate? It will be a "simple" video traffic?
Hope this help.
Stefano Pilla wrote:the "only" thing that differs from a managed switch and an unmanaged switch is that with the first you have a more controlled scenario (please pass me this differentiation ). This means that with a managed switches you can, for example, create Vlans, manage single ports, query the switch, etc...
That's not quite true.
Most "unmanaged" switches are little more than hubs with a MAC table built in (I.E. they don't flood every packet to every port, but forward only to the port the destination MAC is connected to) resulting in a smaller collision domain. They lack the features of true "managed" switches like VLAN's, trunking, remote management etc etc.
To answer the OP's question - if the device "beyond" the unmanaged switch is capable of being managed remotely (I.E. via SNMP or some similar protocol/program), then the fact that the switch is unmanaged won't affect the ability to do so - if you can get data (I.E. video) off the camera, then you should be able to get control/monitoring off it regardless of the type of switch/hub it's connected to.
If the port on the SWITCH or the switch itself has an issue, then you're out of luck - the unmanaged or "dumb" nature of the switch will just mean it, and the camera, will stop working.