What would be the optimum LAN setup?

[Johno]

My home ethernet network consists of two gigabit switches (call them A and B) in different parts of the house, each connected to ports 1 and 2 of my router. All TVs and other AV gear and a printer are all connected to switch A; a few PCs and a NAS are connected to switch B. Now given that the TVs and AV gear play back content from the NAS, I'm thinking that it'd be better if switch B was directly connected to switch A rather than to the router as the path of traffic between a TV and the NAS via the from the current setup is TV -> switch A -> router -> switch B -> NAS but with switch A and B directly connected would be TV -> switch A -> switch B -> NAS

My question is, would there be any noticeable difference in performance between the above setups? Obviously I could test it myself by just changing the connections between switch B and the router but I've no way of objectively testing for any performance difference, if any.

 

[L&LD]

Ideally, you would be using all your router ports. Don't forget, your router has a built-in switch too.

• One port directly connected to the NAS.
• One port directly connected to a switch for all your PCs.
• One port directly connected to a switch for all your TVs.
• One port directly connected to a switch for all your other AV equipment.

With the above configuration, all equipment has equal access to the NAS. And all equipment has equal access to the ISP.

You can also play around with the above suggestions if your router has more than 4 LAN ports (or more) to physically group devices that 'talk' to each other the more frequently than not.

In the end though, unless the LAN ports are utilized 100% 24/7, there will be no effective difference vs. what you have now.

But I would still use all 4 LAN ports if you want the network to be as fast as possible no matter what your usage is.

 

[Johno]

Yes your ideal suggestion makes perfect sense but I'm limited by the number of available RJ45 sockets near the router - two are used for the switches, one is used for another router working as a mesh mode and the one is for the WAN connection from a VDSL modem that's out of sight in the garage.

Thanks for the practical advice

 

[Klueless]

I'm going to take a slightly different tack; rather than "hop count" let's look at bandwidth and "pinch points".

Your NAS has Gigabit so that's the best it can do. Switches A & B also have Gigabit connections. So on a clear day everyone is Gigabit happy.

Now let's say one of the PCs on Switch B is yacking his butt off, I don't know, bit-torrent over the WAN or something. That PC is consuming a chunk of the Gigabit bandwidth of the wire that connects Switch B to the router. So now a "Switch A Client" of the "Switch B bound NAS" has to go through that semi-congested Gigabit wire.

Know up front I think for most of us this is an inconsequential nit but, to continue with my (so called) thinking;

A switch has multiple Ethernet ports. They are "glued" together with, for lack of a better term, a "backplane". In at least some switches that "backplane" will be "Greater Than" Gigabit.

So, if you have two things, on the same switch, talking to each other, at Gigabit speeds, it is entirely possible (depending on the switch) that there is still "uncompromised" Gigibit available (via the 'backplane") for a couple more clients.

With this in mind I would simply try to locate my service on the same switch as the bulk of its clients.

Are we having fun yet?

 

[Johno]

Are we having fun yet?

Everything you've said makes perfect sense so bearing that in mind it'd make sense to have two gigabit connections to the NAS - one from each switch. The NAS is a QNAP 4 bay with 4 ethernet ports.

 

[Klueless]

Everything you've said makes perfect sense

<lol> I'm going to show this to my wife, she claims I never make sense : -)

... it'd make sense to have two gigabit connections to the NAS - one from each switch?

From "five miles up" it sounds good but the devil is in the details. I have no idea if the client and the NAS would negotiate using the "correct" (as defined by us) port.

My guess is the client would simply get whatever NAS port is currently showing lower utilization?

Because you haven't articulated an actual problem my assumption is we're just having a conversation.

4K video is about 25 Mbps. 25/1000. 2.5% Many clients just plain don't consume that kind of (Gigabit) bandwidth. And other clients, like the cheap stuff I buy, couldn't go at Gigabit speeds no matter how hard they might try.

I'm cheap. I'm lazy. Some things just aren't worth touching. If I've only a couple cars on the highway I don't need to build a Thruway ... yet.

Edit: You don't mention what router you're using but if it's an Asus then do take a look at your traffic monitor. Because most of your Ethernet traffic goes up and down router ports (your current design) you can look at the aggregate Ethernet traffic. You might be surprised at how little is actually used?

 

[Johno]

I believe each NAS port would be a separate IP address with a separate host name. My router is an Asus AC68U and the NAS is assigned a fixed IP address by DHCP, so if I did connect to a second port of the NAS from switch A then that'd be a separate MAC address to which I could assign a second fixed IP address from the router and have the all the traffic on switch A use that.

Your mention of how much bandwidth is used by 4K video for me just reinforces the point that cat5e ethernet is more than enough for any home network and when 10Gb becomes commonplace and reasonably priced, I'll just upgrade the switch in the office used by any 10Gb clients and a 10Gb NAS so that file I/O is faster.

Oddly enough I've never thought of monitoring the traffic on the network when streaming HD or 4K content and/or downloading large files from the web so will make a note to do so in future.

 

[Johno]

Well I've connected a second port of the NAS to switch A and assigned a static IP via the router DHCP and it reports the same hostname, so the only way to use the second NAS port is to refer to it by IP address. I'm running iPerf3 on the NAS and when running iPerf3 on my ethernet-connected-to-switch-B laptop I'm getting 945Mbps reported when connected via the NAS IP address that's connected to switch B, but 923Mbps when connected the NAS IP address that's connected to switch A - a small difference and probably nothing that'd be noticed in real-world use at home, but it's a shame that the QNAP doesn't let me identify each network port via different hostnames. If the router could do VLAN then I'd probably segregate switch A and switch B so that the TV and AV gear can't see the PCs and everything else but could still access the NAS via the switch A connection, but that's a job for a more advanced router, maybe a Ubiquiti Dream Machine sometime in future...

 

[Klueless]

I'm running iPerf3 on the NAS and when running iPerf3 on my ethernet-connected-to-switch-B laptop I'm getting 945Mbps reported when connected via the NAS IP address that's connected to switch B, but 923Mbps when connected the NAS IP address that's connected to switch A - a small difference and probably nothing that'd be noticed in real-world use at home

So like a 2% hit. Actually I'm kind of surprised it's even that "much". Even so it doesn't seem worth the effort. And if a 4K stream is only 25 Mbps then it's only a 0.5 Mbps hit. I'm thinking it's all moot. That said I do admire your efforts.

If the router could do VLAN then I'd probably segregate switch A and switch B so that the TV and AV gear can't see the PCs and everything else but could still access the NAS via the switch A connection

Not sure I see the benefit. Once the traffic has to pass over the single wire between the router and switch it's traffic, VLAN or not.

 

[Klueless]

cat5e ethernet is more than enough for any home network and when 10Gb becomes commonplace and reasonably priced, I'll just upgrade the switch in the office used by any 10Gb clients and a 10Gb NAS so that file I/O is faster

Last I read 10 Gig over CAT5E was "debatable". Maybe 50M rather than the full 100M spec?

 

[dosborne]

but it's a shame that the QNAP doesn't let me identify each network port via different hostnames

Why is it a shame?
Hostnames just get refered back to actual IP addresses using DNS, WINS, etc. Using an IP is actually better and faster (although imperceptible).

For your scenario I can't see where the various layout options will make any real difference.

The best advice is see above is to connect the various devices that talk to each other on the same switch if possible. If not, doubt you would see any difference.

*IF* your NAS is providing a heavy load on your network, then you could look at port trunking depending on which QNAP model you have.

 

[Klueless]

I think roadways are somewhat comparable to networks.

Multiple 2-lane, 30 MPH side streets connecting to 4-lane, 45 MPH highways connecting to 70 MPH expressways.

But networks are often upside down. Clients (side streets) have ready access to extremely affordable Gigabit connections and the Internet (expressway) is too often constrained by, say, 7 Mbps DSL pipes to the Internet.

Stealing from dosborne; You have multiple Gigabit clients (side streets) connecting with the NAS. So you take two Gigabit ports and gangbang them together to create a 2 Gigabit highway to the NAS. Then you put everything on the same switch and take advantage of the high speed backplane as the expressway.

But if most of your clients are simply 4K streamers @ 25 Mbps all sharing a Gigabit pipe to the NAS this whole exercise is likely moot. Sometimes it's cheaper/easier to design to "reality" rather than "theory".

Another thought as long as we're just messing around; If you keep clients on a separate switch than the NAS then you have an added point of failure as opposed to putting everything on the same switch. If you use both switches you go down if either switch goes down. If everything is on one switch you're only impacted if that switch goes down : -)

 

[Johno]

So like a 2% hit. Actually I'm kind of surprised it's even that "much". Even so it doesn't seem worth the effort. And if a 4K stream is only 25 Mbps then it's only a 0.5 Mbps hit. I'm thinking it's all moot. That said I do admire your efforts.

Not sure I see the benefit. Once the traffic has to pass over the single wire between the router and switch it's traffic, VLAN or not.

It's interesting for me I guess and adds to experience

The only benefit of separate VLANs would be segregation of network traffic for security, but yes, as you say the same performance bottlenecks still exist.

 

[Johno]

Last I read 10 Gig over CAT5E was "debatable". Maybe 50M rather than the full 100M spec?

I've read that 2.5Gbps is capable over cat5e, though given the relatively short cable lengths that are more likely in a domestic environment, maybe higher is achievable but I guess nowhere near 10Gbps