help with multiple switch fabric config

[Brucek750]

Hi All- I volunteer at a local non-profit/non-sectarian school here in North Carolina and the school is growing quite a bit and I need help in updating the design of the network. To save money, most of the network components were donated and/or purchased used off of eBay, but I have assembled what I believe to be a fairly good infrastructure; I just need help in deciding how to lay it out.

The incoming cable connection is a 40/5 TWC cable modem connected to a Asus RT-AC68U wireless router running Merlin’s latest firmware; There are five Asus RT-N66Us configured as wireless access points. The school will soon be upgrading to a 100/10 connection. The AC68U is also configured as the DHCP server.

Here is my dilemma: The main Ethernet fabric consists of three 48port 3Com 5500-EI switches currently configured with fully redundant ‘XRN’ stacking which uses two gigabit ports on each switch to interconnect the three switches and can be managed as a single entity. I have a single gigabit lan port connected between the router and the top switch. It seems to me that this would be the correct configuration in a normal business with multiple servers, but since the school has no servers (probably 98% of the Network traffic is destined for the public internet), I should ‘break’ the XRM switch fabric, and connect each switch directly to one of the four ports on the main router- or should I leave the XRM fabric in place, and connect the Wireless APs directly to the main router? Currently the APs are connected to the gigabit ports on the 3com switches (each switch has four gigabit ports, but two of the gigabit ports on each switch are dedicated for the XRM connection).

I do not use any VLANs; there are ~110 wired clients, and ~150 wireless clients (mostly ChromeBooks and iPads). I have just now started to investigate enabling link aggregation between the router and switch fabric.

I apologize for the lengthy question, but I would appreciate any insights/suggestions!

 

[coxhaus]

If the switches were designed to be backplane linked or stacked as one unit then you have it connected correctly. They are working as one switch. This is the best way to stack switches. Do not divide them as it is not as efficient.

PS
Nothing wrong with LAG but your internet is so slow compared to the GIG up link that I don't think a LAG will make any difference, maybe redundancy in case a wire goes bad but not speed.

 

[Brucek750]

Thanks Coxhaus!

 

[Cloud200]

There is one thing you can do for redundancy.
Connect an ethernet cable on port 1 of the router to Switch A, and call it 1A
Connect an ethernet cable on port 2 of the router to Switch B, and call it 2B

Confirm that you didn't break anything and that spanning tree is working as intended.
If spanning tree is not working correctly you will either lose all access to the network or just the router until the 2B is unplugged.