DSM-G600, DNS-3xx and NSA-220 Hack Forum

Your 2 devices are assigned IP's thru your router, thus, are bottlenecked by your router. It's only as fast as the weakest link.

Now if you were using a crossover cable or took your router out of the equation, then you'd be running gigabit.

madpenguin wrote:

Your 2 devices are assigned IP's thru your router, thus, are bottlenecked by your router. It's only as fast as the weakest link.

I do not believe this is correct. 

If you have two gigabit devices on a gigabit switch, then the connection between the those two
devices will be at gigabit speeds (although the devices themselves might limit the throughput). 
The speed of your internet connection (through the router) will be bottle necked at 100Mbs speed.

There is this issue of flow control http://www.smallnetbuilder.com/content/view/30212/54/
but this is a case where a gigabit device is trying to transfer to a fast Ethernet device and a
gigabit device at the same time.

Last edited by mig (2009-01-14 07:33:31)

Short answer: They will NOT be limited by the router.

Long answer: the typical home router is an Internet gateway, a DHCP server, and a switch combined into one. Say you have a router and two PCs in your household, and you connect all of them to the same gigabit switch. Your PCs will use the Internet gateway and DHCP parts of your router functionality just fine, but if the two PCs communicate between themselves, the data does not need to pass through the switch inside the router. The gigabit switch will handle the communication.

It helps if you envision both the router and the two PCs as discrete and roughly stand-alone nodes connected to the same network (through the gigabit switch). It then *roughly* works like this:

1) You turn PC 1 on.
2) PC 1 sends a broadcast onto the network saying I need an IP.
3) PC 2 (if it's on) ignores this broadcast because it's not a DHCP server and doesn't know how to respond.
4) Router receives the broadcast and communicates with PC 1, offering it the IP as well as any other relevant information (gateway, etc). This enables PC 1 to communicate with the Internet through the router.
5) PC 1 and PC 2 communicate with each other only through the gigabit switch. Router doesn't need to get involved.

Of course, if you connect one of your PCs directly to the router (i.e. the switch in the router), then its communication has to go through the router, and thus is limited to 100M.

Hope this helps.

Last edited by blahsome (2009-01-14 17:52:03)

blahsome wrote:

In fact, that's exactly what I'm doing nowadays. My router is a 100M Linksys WRT54GL, whose third-part firmware is orders of magnitude more capable than the stock firmware of most residential routers with a built-in gigabit switch. Therefore, I have indefinitely delayed my next router upgrade and just purchased a couple gigabit switches for my network.

Works perfect.

Exactly my same set up as well, even down to the WRT54GL running dd-wrt.
I have 2 DLink Gigabit switches connected to each other that run the "core" of my home network, and the router is now just there only for when I need to get off my home network to the Internet.

blahsome wrote:

In fact, that's exactly what I'm doing nowadays. My router is a 100M Linksys WRT54GL, whose third-part firmware is orders of magnitude more capable than the stock firmware of most residential routers with a built-in gigabit switch. Therefore, I have indefinitely delayed my next router upgrade and just purchased a couple gigabit switches for my network.

Works perfect.

I have a similar setup, but with "residential" hardware - a D-Link DI604 router (10/100) connected to a Netgear GS105 gigabit switch. I have a question about this. Since all the devices behind the router are on the same subnet, I think I can't use jumbo frames unless the router supports them. Is that correct?

If so, and if support for jumbo frames on 10/100 routers is rare to non-existent, is this a reason to acquire a gigabit router?