Connecting a switch to a router twice

[blackbird307]

The idea is to create a backup connection. So if one fails, the other can backup automatically. But I am not sure if this will create switching loop.

Maybe someone can suggest a better idea if this is not possible?

Thanks,

 

[jsmithepa]

This will create a loop.

Are you trying to redundant cabling or are you trying redundant boxes? and if cabling, why do you think it may fail? are you running it over public pavement or something?

 

[blackbird307]

Redundant cabling. The cable is going from one building to the other. If one fails, there will be a backup. Both buildings are going to be part of the same network.

The chances are if one cable fails, they're both going to fail in any event. Personally, I would just stick with one. Regardless, this is the plan, I am not going to question it.

 

[jsmithepa]

Am almost certain the way you want it hooked up is going to cause problems, but u can always experiment, the worst is, it won't work, nothing is going to blow up.

"Out there" network designers are worried about boxes redundancy, and a box failing may take down all the connections with it, like a road closing, so the designer places backup boxes (multiple switches), in the ready in the event that a box fails. The switches talk to themselves via a TRUNKING protocol, and knows when the main path has failed, then turn on the backup path, but NEVER have both paths turned on at the same time. The trunking protocol does this automatically and in real time. The switches capable of doing this costs thousands of dollars.

Routers, again building redundancy, means duplicate redundant boxes which provides MULTIPLE PATHS TO A DESTINATION, which helps if a link (i.e. cable down by a construction digger), but multiple routers are more intelligent and can load balance as well as for failsafe. This stuff of course is for enterprise networking, 24x7 up time mandatory, am guessing not the expense you have in mind.

 

[AgPaul]

this is very easy to set up as long as you have the right hardware.

you will at least need a small business grade router and managed switch. they must be capable of using Spanning Tree Protocol. thats very important. without STP you can't have the exact redundancy you're looking to create. in addition to STP, a switch that is capable of Etherchannel or Link Aggregation protocol will give you some really nice features that STP can't do by it's self.

 

[digitaldoc]

If using consumer hardware, I would only make one connection from the router to the switch. I am concerned of stability, and as others said, it would not load balance.

If you are trenching the wire, or worried about the longevity, you could always run the two wires, but only connect one of them at a time.

 

[cdheer]

Agreed with AgPaul. I'd be very surprised to learn that a consumer switch and router support STP. If this is enterprise-class gear, that's another story.