LAN best practise for Routing

[#1]

Hi Guys

My first question on here and nice to meet you guys.

Current network design is as follows.

1841 Router connected to Core 3650 L3 switch.

Routing enabled on Core with SVI's.

4x VLAN's, 1,5,10,71 (Management, Users, VOIP,etc.)

I have 4x 2960x switches connected to the 3560 on the uplink ports as trunks. The 2x additional 2960x switches in the same cabinet is linked to the 3560 via uplinks and the rest of the other switches in the nearby buildings are connected to the additional 2x switches via their respective uplinks ports.

My problem that i have is  that i am running out of uplink ports in the server room where the Core and 2x switches are hosted. If i decide to connect additional switches or devices via the available uplink ports, then i am just daisy chaining it and creating problems for myself.

I was looking at getting a 3750G 12x port sfp switch to solve this problem.

So my question is then, how do i configure the the 3750G 12x sfp switch to connect to the 3560, which is the Core switch and then configure and connect all the other switches on the 3750G.

Would appreciate your guys feedback on the best way to go about it. A 4500 switch will be an overkill as the site has about 500 users.

[Mark Malone]

Hi

You have a single point of failure there in that design with your core switch , if that fails your networks offline and nothing can even speak to each other locally  , you could get another 3560 switch stack the 2 of them together give yourself some resiliency and split the access switches over both switches in port-channels with a  link to each switch in the stack

if you cant stack , I would link the switches by hsrp or some other fhrp like gblp to give you redundancy at core level again linking access switch to each core switch   , just my opinion though if it was doing it , I would be looking at resolving the port count and also strengthening the design as much as possible with what you have

you're right not to daisy chain avoid it where you can

[#3]

Hi,

Thanks for the feedback. You are correct in the sense of redundancy at the Core switch. My main problem is the 9-10 uplinks which all the switches piggy back off some. If i do get another 3560 to stack or hspr, then i still sit with an issue with daisy chaining.

I'm looking at a longer term solution atm.

[Joseph W. Doherty]

You initially note your L3 is a 3650, and later it's noted as a 3560.  Which is it?  If it's a 3560, is it a 3560G?

(For no [?] additional cost . . .)

If you interconnect your core L3 with your two 2960X in the same cabinet using copper, you could support up to 12 fiber downlinks, correct?  If so, is that sufficient for your needs?  (Yea, you would have some downstream switches hopping through a single 2960X, but I don't see the one additional hop as a show stopper.)  If you need more fiber downlinks, you could also add another L2 switch at your core rather than a more (?) expensive L3 switch.

If you have bandwidth concerns about jumping through your core L2, select the lowest bandwidth remote L2 switch to connect to the core L2 switches and/or copper Etherchannel between the core L3 and core L2 switches.

As Mark notes, your core L3 is a single point of failure, but that can be addressed by having your 1841 do FHRP with your core L3 switch, for it to be connected to one of the core L2 switches, and for your VLANs be trunked across all the core switches and for the two L2 core switches to be interconnected.  (I.e. the 1841 would take over for the L3 switch, although it won't have anywhere near the forwarding performance.)

[#5]

Sorry, it's a 3560.

I going to try and see if I cannot get a fibre switch to solve my problem, if I cannot I will get stacking modules and cables to make the L2 switches as 1 switch and also by freeing up 2 or 3 sfp uplink ports.

Wrt to redundancy I will do the setup you suggested.