Router to work as a switch?

huldu

Distinguished
Aug 5, 2011
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18,510
A switch and a router are both pretty straight forward in regards to how they work. Tho I have a problem with the router.

I have 5 computers in my home and we have 5 different ips for the computers to use, these are handled by a switch. <Note: these are 5 *unique* ips that does NOT share bandwidth>

Recently I got a router and when I plugged it in it only gave us 1 ip to share amongst all 5 computers. This is a pretty big problem as we all of the sudden *share* the bandwidth. <Edit: the problem is that the router only gives us 1 of the 5 ips for the whole network to share>

What I wonder is what is it called when you get a router to accept multiple external ips and spread them out across the network, like a switch does? I assume this is a "special" feature on routers?

Honestly I have no idea, multi-wan, multi-nat, multiple external ips... I've searched for quite a few things and found very little information on this subject because I'm looking in the wrong places.

Any help would be greatly appreciated!
 


The router is a sort of switch with extra facilities, and the only way it can offer the same IP so more than one system is if DHCP isn't turned on so that's the settings you're looking to change. I've never seen one that can behave that badly straight out of the box - was it new when you acquired it? The external IP is nothing to do with this.


 

john-b691

Honorable
Sep 29, 2012
703
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Your problem is that it is not as straight forward as you think. You really have to understand how routing and subnets actually work to understand why you cannot do what you are proposing. Normally to use multiple IP the ISP would ROUTE the block to the wan address of the router. What you are looking at doing is having the router somehow assume multiple IP on its wan interface within the same subnet.

To make this work you are in effect going to trick the ISP router into sending traffic for what it thinks is 5 actual machines to a single router. It is unlikely you are going to be able to find a consumer router that can do this. A commercial cisco router you could put in static route with a /32 subnet and then manually map ip to mac address and make this work because of a feature called proxy arp. Still just because a network professional like me COULD make this work it is not something I would ever do.

Not sure why you would want to even do this. You can easily put in a switch and plug in 5 routers and then if you are careful you could connect the lan side of these routers together.
 


Unless he's using a business account at home, I doubt his ISP is assigning him a block of addresses. The OP seems to have his definition of router and switch reversed as switches don't hand out IP addresses.

I think saga layout is on the right track. It sounds like DHCP is disabled in the OP's router and just needs turned on.
 




I'm glad about that - I've never seen a switch with five routers plugged into to it but my own route does have three switches plugged into it.