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-   -   Network connection - which way? (https://www.cableforum.uk/board/showthread.php?t=33629423)

LSainsbury 04-03-2008 14:59

Network connection - which way?
 
OK - say you have a PC running a 1Gig LAN connection to a 1Gb switch using a CAT 5e / 6 cable.

On the same switch you have a NAS device with is also 1Gig capable and also using a CAT 5e / 6 cable.

Connected to the switch is a Linksys router running 100Mbps.

When I transfer files from the PC to the NAS would it go direct to the NAS through the switch at 1Gbps or would it have to go to the router in order to route the packets back to the NAS - thus being a bottleneck?

OldGeezer 04-03-2008 15:48

Re: Network connection - which way?
 
The packets would just go through the switch, not to the router.
You can tell that by which lights are flashing!

Roughly speaking the switch is aware of what is hanging off each port (by looking at the "source" MAC address in the packets that come into it). The destination of a packet coming into one port is looked up and the packet is directed to the matching port.

LSainsbury 04-03-2008 16:57

Re: Network connection - which way?
 
Quote:

Originally Posted by OldGeezer (Post 34500070)
The packets would just go through the switch, not to the router.
You can tell that by which lights are flashing!

Roughly speaking the switch is aware of what is hanging off each port (by looking at the "source" MAC address in the packets that come into it). The destination of a packet coming into one port is looked up and the packet is directed to the matching port.

Ahh - but dosn't that depend on what OSI layer the switch is capable of? Hence why I thought the router might be involved somehow to re-route the packets...

OldGeezer 04-03-2008 17:34

Re: Network connection - which way?
 
Well yes, but your typical SOHO switch would be layer 2 (a hub being layer 1 and a router layer 3/4).

jem 04-03-2008 18:52

Re: Network connection - which way?
 
Quote:

Originally Posted by OldGeezer (Post 34500127)
Well yes, but your typical SOHO switch would be layer 2 (a hub being layer 1 and a router layer 3/4).

At the risk of being pedantic a hub is also a layer 2 device, a repeater (not that you will see many these days) is a layer 1 (physical) device. All switches basically work at layer 2 although there are some which can work at higher layers.

In the OP's case as long as the PC and the NAS are on the same subnet and there are no VLANS involved then data will be switched directly between them. See if you can turn off store and forward on the switch for throughput if it supports it.

LSainsbury 06-03-2008 14:03

Re: Network connection - which way?
 
OK - so would this scenario work as well:

Wireless NIC on 192.168.1.x connecting to a wireless router

Gigabit NIC on 192.168.2.x connected via GB switch. Attached to the switch is a NAS and printer - would both work?

RDDearing 06-03-2008 15:13

Re: Network connection - which way?
 
Assuming you've taken care of the routing (after all, 192.168.x.x is a class C address range so you're using two different subnets) then the gigabit NIC will use the NAS at 1Gbps. Since the wireless NIC is connecting via the router (which has been stated at 100Mpbs) then the wireless NIC will use the NAS at either 54Mbps (assuming you're using an 802.11g card) or 100Mbps if router/nic allow a "turbo" mode.

As for the printer, depends on the speed of the NIC but even on 100Mbps there are so many other factors that will dictate the speed of printing!

LSainsbury 06-03-2008 15:21

Re: Network connection - which way?
 
Quote:

Originally Posted by RDDearing (Post 34501454)
Assuming you've taken care of the routing (after all, 192.168.x.x is a class C address range so you're using two different subnets) then the gigabit NIC will use the NAS at 1Gbps. Since the wireless NIC is connecting via the router (which has been stated at 100Mpbs) then the wireless NIC will use the NAS at either 54Mbps (assuming you're using an 802.11g card) or 100Mbps if router/nic allow a "turbo" mode.

As for the printer, depends on the speed of the NIC but even on 100Mbps there are so many other factors that will dictate the speed of printing!

Not too worried about the printing speed - it's the NAS I want to run at gig speeds.

dragon 06-03-2008 18:11

Re: Network connection - which way?
 
My network goes pc > 100Mbit switch > powerline > router.

My Nas Is on the same switch and I get fairly close to 100Mbit/s to it.
Sometimes a Little less if Id used SCP since the nas was only a p3 500 i suspect it was encryption overheads (nas is now a dualcore athlon)

Jon T 06-03-2008 18:50

Re: Network connection - which way?
 
Your switch will contain a table of what MAC addresses can be reached on each of it's ports. When your PC wishes to communicate with your NAS for the first time it must try to find out it's hardware (MAC) address, this is done by transmitting an ARP broadcast that basically says "respond if you are the device with IP address X.X.X.X." The next time the PC wants to talk to the NAS, the mac address it has learnt in the previous step is included in the IP packet. The switch then knows to only send that packet out on a specific port.

Splitting IP ranges and having to manually construct/edit routing tables is not needed in your situation at all. The packets from your PC that are destined for you NAS(and vice versa), won't go anywhere near you router.


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