Gigabit Ethernet Requirements

[artemicion]

Sorry for the basic networking questions, but Google couldn't give me a definitive answer.

I am wondering what networking scenarios are necessary for a gigabit ethernet connection to exist between two points on a network. Assuming the following hardware:

1 DSL Modem/Router without gigabit ethernet
1 Router with gigabit ethernet
1 computer with gigabit ethernet
1 NAS with gigabit ethernet

The way it is currently setup, the DSL modem/router is the main router. It has a wired connection to the second router with gigabit ethernet. However, DHCP is disabled on the gigabit router and DHCP is handled by the DSL modem/router.

If the computer and NAS are connected to the gigabit router, will the fact that DHCP is handled through the non-gigabit router prevent a gigabit connection between the computer and NAS?

If so, would I be correct in assuming if the routers are configured such that DHCP is handled on the gigabit router, this would allow a gigabit connection between the computer and nas?

Thanks in advance.

 

[Dahak]

If the computer and NAS are connected to the gigabit router, will the fact that DHCP is handled through the non-gigabit router prevent a gigabit connection between the computer and NAS?

No

simply put if you connect to a device into a gigabit device, ie the gigabit router or switch it will connect at gigabit speed.

DHCP has nothing to do with the connection speed

 

[RadiclDreamer]

As long as the L2 path along the way is gig you are fine, the DCHP server can be 10mb and you would still be ok

 

[azazel1024]

L1 path you mean. L2 has nothing to do with it.

 

[RadiclDreamer]

L1 path you mean. L2 has nothing to do with it.

Actually it does have everything to do with it, L1 deals with the physical aspects only, the electrical signals and light pulses and wireless waves etc. The L2 deals with ethernet frames which include the source and destination mac address in the frame header which ultimately determines the path.

 

[artemicion]

OK thanks, I wasn't sure if DHCP being hosted on one router meant that all the data had to be routed through that router.

I assume it is also irrelevant if there's a non-gigabit device in the network, i.e., two gigabit computers and a non-gigabit computer connected to a gigabit router would still permit the two gigabit computers to communicate to each other at gigabit speeds?

 

[RadiclDreamer]

OK thanks, I wasn't sure if DHCP being hosted on one router meant that all the data had to be routed through that router.

I assume it is also irrelevant if there's a non-gigabit device in the network, i.e., two gigabit computers and a non-gigabit computer connected to a gigabit router would still permit the two gigabit computers to communicate to each other at gigabit speeds?

That is correct.

To clear things up, all dhcp does is assign an IP address, it does not become involved again until the lease expires and needs to be renewed which is variable.

As for devices communicating, as long as the network electonics from end to end support a given speed the two devices will communicate at that speed, though if you have a gig switch connected to a 100mb that is then connected to a gig, anything traversing the 100mb switch will be limited, however all devices plugged into gig switch 1 will talk to each other at gig and all devices on gig switch 2 will talk at gig, but anything talking from gig switch 1 to gig switch 2 will be 100mb because they are tied together with a slower device.

Think of it in terms of plumbing, the smallest pipe in the run determines the flow, even if you have 8inch pipes all through the run, but have a 1inch in the middle, you are limited to what a 1inch can handle.

 

[azazel1024]

Actually it does have everything to do with it, L1 deals with the physical aspects only, the electrical signals and light pulses and wireless waves etc. The L2 deals with ethernet frames which include the source and destination mac address in the frame header which ultimately determines the path.

If you are meaning if it travels down a 100Mbps path at some point because of the way the packets are switched, then it is effectively a 100Mbps connection? Yes. However, that is still the L1 path you are concerned about. L2 has nothing to do with the actual performance of the path (well, okay, packet size will determine speed, to a degree).

The physical aspects here are what matter. Is the L1 path gigabit the whole way, or is it not?