Confused about gigabit switch/jumbo frames/router

[Jeraden]

I spent the last hour trying to figure out what the deal with all this stuff is, but I still don't completely understand.

Let's say I have 4 PCs at home. 3 are gigabit lan, the 4th is not. Right now they are all hooked up to a 100Mbps router, for internet/network sharing.

I want to get a gigabit switch so the 3 gigabit PCs can transfer data faster. Ideally I'd like some Jumbo Frame support to make it all more efficient. This is where I'm confused. Can I even do this since I still have a PC that does not have gigabit lan (its a laptop that connects to the wireless router).

If I set all 3 gigabit PCs to use jumbo frames, hook them up to the gigabit switch, then have the gigabit switch hooked up to the non-gigabit router, will that work? Or will the fact that the PCs are using jumbo frames and trying to communicate with the non-jumbo router cause communication to fail?
I keep reading conflicting information.

If I don't use Jumbo Frames, I'm assuming the gigabit switch won't pose any problems, or am I going to run into issues there too?

Or is the switch really only helpful with jumbo frames if I keep it as a separate subnet, so I'd need 2 network cards in each of the 3 computers - 1 for jumbo frames communication between the 3 pcs through the gigabit switch, and the other connection to the router for general internet/network sharing?

 

[megamojo]

Jumbo frames still don't work very well in real life. In order for them to work properly, every device on the network segment must support jumbo frames. When I say network segment I mean any traffic that doesn't pass through a router, which in your case is everything except communication between you and the internet. Traffic between your PCs that are both connected to the router isn't really going through the router, it's going through the switch that is built into the router. Right now the easiest way for most "normal" people to truly use jumbo frames is the make sure all workstation PCs support jumbo frames and have them turned on and to make your own router out of an old PC and one of several router distros of linux/unix, such as IPCop, Smoothwall, m0n0wall, etc., and use a jumbo frame supporting NIC in the router. You could also set up 2 subnets as you said, but that can be more trouble than it's worth. We need to wait a few more years before jumbo frames are actually usable by most people.

 

[JackMDS]

Practically, Jumbo Frames means setting the MTU of the TCP/IP Stack to 9000.

Since an optimal MTU for Cable Internet is 1500, and for DSL 1492. Setting your System to Jumbo frames would Sc*** your Internet connection.

So leave it alone, or if you have a system that can really benefit from MTU=9000.

Read This, http://www.ezlan.net/giga_net.html

:sun:

 

[Madwand1]

Originally posted by: Jeraden
If I don't use Jumbo Frames, I'm assuming the gigabit switch won't pose any problems, or am I going to run into issues there too?

Unlike jumbo frames, gigabit itself has been standardized in a manner which makes it compatible with 10/100 ethernet. So yes, this should be fine.

 

[her209]

I had jumbo frames enabled on my gigabit NICs and didn't notice any performance gains at all. The MTU size was set to the lower of the two max MTU supported size on both NICs.

 

[bruceb]

You need a Gigabit Router to properly feed your Gigabit Switch
The computers can only go as fast as their processors & NIC Cards
You will also need a very high speed cable internet or faster for this
to work properly ... on dsl, you would not see much of an improvement

 

[wallsfd949]

Originally posted by: brucebYou will also need a very high speed cable internet or faster for this to work properly ... on dsl, you would not see much of an improvement

He won't see any improvement at all in his internet speeds with either cable or DSL. He would need an OC-3 or an OC-12 to start to benefit from Gigabit connectivity on the WAN side. He was referring to the LAN / intranet side.

You can't get Gigabit SOHO routers with Gigabit support for the WAN side. No one spends $10k+/mo for internet @ home.

 

[bruceb]

Then he would be wasting money spending for a Gigabit Switch
He would not see any improvement over a 100MBS Switch

 

[Jeraden]

The reason I wanted increased speed is I have a main HTPC that I record lots of tv shows/store DVDs/music/etc on. Its a pain in the butt transferring files to it over the normal 100Mbps router. Just takes a really long time.
I'm adding a new computer to my network and I'm actually out of inputs on my current router, so I need to get a new router/switch anyways so it made sense that I might as well get a gigabit one since I need a new one anyways and I have 3 PCs now that have built-in gigabit ethernet.

Anyways, thanks for the advice, sounds like I might as well just get a cheaper one and not worry about jumbo frames since I won't be able to get every single computer to use them.

 

[JackMDS]

Router is a Router, switch is a switch. It just happed that the Router and the Switch are sold as a combo in the same Plastic Box calles Wireless Cable/DSL Router.

LAN traffic is only a matter of the Switch.

Given the sum of all of your postings, get a simple 1000 Mb/sec. Switch (some are sold for about $30) plug it to a regular port on your current Router and connect all the Giga capable computers to it.

The result would be at least doubling you current LAN Speed.

Giving you circumstances any other solution would cost three to four times more and would yield the same.

:sun:

 

[imaheadcase]

Hi i was about to post in this very same thread. I found this link helpful im not sure if i got it here or some other forum.

http://www.ezlan.net/giga.html

From what i've read you can get Jumbo Frames support with Windows Vista because they rewrote the whole networking code and includes support. So what i did was get 2 Intel Pro nics for $34 each they support jumbo frames. They got me a switch that supports jumbo frames (still looking around for one i want). So its just a matter of upgrading to Vista when its out if your not into the whole Other OS thing like myself. Lots of switches out now under $100 that support jumbo frames, you just have to look around.