Hub & Spoke vs Mesh topology

[Sanman]

Hi 

I have a set up of around 150 sites with 1 DC. There are also around 10 other sites that hosts applications. Hub and Spoke to the 1DC would create suboptimal routing for some sites especially some international sites. And doing a full mesh means that a lot of sites (90%) with smaller boxes would not be able to support so many tunnels (I have see the formula to calculate number of tunnels).

Is multiple HUBs a recommended solution? In my case there will be close to 10 sites with servers and applications. Consolidation of applications to Hybrid (on prem and cloud) is still 2 years down the line. What are some of the challenges if we go ahead with 10 HUB and spokes selectively choose their appropriate hubs. 

Jay

[alemabrahao]

I don't see a huge benefit to using full mesh.

The biggest and only difference I see is that the MXes will have a direct route to each other, without the need to go through a specific HUB.

In most deployments I've seen the most common is to use hub and spoke.

[MerryAki]

I would reduce the amount of Tunnels to a minimum, in order to comply with HW regulations.

[Sanman]

I agree with both above. if I have a site that requires access to 3 HUBs (application resides on three locations for this spoke). can I go directly to these 3 sites or will Meraki choose a primary DC and route application to other 2 DC via the primary HUB?

I am trying to see if there are any challenges with creating multiple HUBs.

[Ryan_Miles]

I'd recommend you have a design session with your Meraki SE on this one.

But yes, you could take an approach of regional hubs. Full mesh tunnel count can get high real quick especially if you have dual WAN links on the MXs. 150 sites of full mesh with single WAN links would be 149 tunnels per MX. So per the MX Sizing Guide you'd want to have MX95's minimum.

If this is an international deployment perhaps designate one hub (or HA pair) per region and then have local spokes use that as primary and maybe use another regions hub as the secondary. 

[PhilipDAth]

You can quite happily enable 10 HUBs.

There is no Meraki device that you could use as a spoke that won't be able to handle 10 hubs.

For the 10 hubs - they'll need to be MX95s or bigger.

[Sanman]

Thank you. if there are 10 HUB and as an example if a spoke needs to communicate with 3 HUBs, does the traffic to all these HUB go directly to the HUBs? Just wanted to be sure. This is my last question for this post. 

[PhilipDAth · Accepted solution]

Correct.