To LAG or not to LAG (LACP)

[mickeko]

Hi,

I'll just start this out with posting a picture:

Isn't that a pretty...

Gear list:
Switch A: Netgear GS108T
Switch B: Cisco SLM2008
Router: Ubiquiti EdgeRouter PoE-5
WIFI: Asus RT-AC68U (AP mode)

Additions (to be connected to Switch B):
NAS - Brand/Model TBD
VPN Router - Most likely a Ubiquiti EdgeRouterX


Left side is my current configuration. WAN comes in, is patched directly to LAN1 and connects to the router, which is then connected on to my wifi and also patched back into the rest of my LAN. Simple enough. There are several reasons as to why the router is not connected where switch 1 is, it's not currently an option unfortunately.

Right side is what I have in mind. WAN comes in to switch A (VLAN2 configured port), goes via the LAG trunk to switch B (VLAN2) and on to the router (and wifi), then patches the traffic back to the switch (VLAN1) over the trunk and on out to the rest of my LAN. Unfortunately there's an error in the right side drawing, my wifi AP will be connected to switch B, not the router.

I didn't include it in the sketch, but I also plan a VLAN3 for maintenance purposes. Don't want to leave those configuration UIs (looking at you Netgear...) open on the main LAN.

So, now. Question time:

Aside from looking fancier on paper and having cool abbreviations in it, is my suggested change actually better than what I have (as in potentially faster with 25-30 devices distributed fairly evenly over LAN and WIFI)? Obviously it adds complexity, but I don't have a problem with that. I also plan to connect a second router to be used for VPN (which will require its own local VLAN) and a NAS (for backups and streaming media) to switch B, which is mainly why I'm considering this change in the first place.

Thank you for reading, and I apologise for my lazy sketch. Oh, and if you feel there might be a better way to sort out this mess, I'm open for suggestions. Costs *is* an issue though, I already have all the hardware needed to make my suggestion above happen. If needed I can buy some additional low cost items, but suggestions about switches with 10Gbit trunking ports and whatnots would be a waste of time (I would if I could).

 

[degrub]

What is the change trying to accomplish ?

Is there a documented congestion point with the current layout ?
If so, what is it ?

pretty tough to saturate gigabit switches with home use.

 

[mickeko]

I don't have a problem right now, but I'm worried that adding a NAS (would be connected to the router in the current configuration) with 2 computers (@ LAN3 and 4) accessing it quite frequently might affect the general performance of the network. I need to have as fast as possible access to the NAS and still be able to freely watch my netflixes and keep the latency down for gaming.

 

[System Error Message]

no reason not to as worst case scenario you get the same speed without LACP. You should go ahead if you already have the network for it otherwise you'd have to weigh the need for any compatible network gear. Not all switches do LACP, a lot of them do static bonding instead.
connect the netgear and nas to the cisco switch and perform LACP and static bonding for the netgear, this will eliminate the bottleneck. Connect router to the cisco switch.

The router is also capable of LACP/bonding on it's switch chip however you would need to check which ports are switched and which arent. So using router as a central point if the switch doing LACP also has 2 links to router that helps but there just isnt enough ports to do LACP for both switches on router and connect wifi to it.

 

[sfx2000]

Simon says no - it's not worth it on a small LAN...

LAG can help in highly loaded networks, well beyond what most home/small office/small business can drive....

Remember, in the IEEE/OSI stack, there are limits - with LAG, the limit is each interface... with LAG, it's the ethernet layer itself, as each frame over the wire has to be ack'ed on that wire...

It's like being at the grocery store - one lane vs. many, but one still has to do the time in the lane you pick, even though the collective is faster...

 

[coxhaus]

LAG adds a complexity to home networks which usually is not needed. If I was going to add a LAG port at home it probably would be only to connect switches together. Passing traffic for internet and local data can saturate a GIG pipe with some of the big internet connections available now days.

Some of the home switches do not do LAG very well so setup a test to check it with to make sure you are seeing a benefit from the LAG port.

Routing multiple networks through a small home router may cause slow downs to where a LAG port may not help so choose wisely.

I think multiple networks are best handled by a layer 3 switch.

 

[mickeko]

Thanks for the replies. I probably should have mentioned that my internet connection is symmetrical 250Mbit (considering an upgrade to 500, but it's more a vanity thing than an actual need).

Judging by the answers this seem like a bit of a hit or miss thing. I think I'll just add the new stuff to the network as is and see if things go bad. But I'll probably try changing things anyway when I have some spare time and taking down the internet won't cause too much grief. No matter the outcome, it's still a good learning experience.