Redundant network connections

[Søren_Steinmetz]

I work on a small K12 school with a Meraki network + wireless setup.

To ensure redundancy I prefer to have all switches connected to at least two other switches, but I have been told by external consultants that this can not be done with Cisco Meraki.

I have posted a simple picture with my present connections, and how I would like to "expand" them.

Switches A1, B1, B2, C1, D1 are all Meraki MS (A1 MS320, the rest MS220), C2 and D2 are a different brand and as such no need to have redundant connections.

Am I wrong or the external consultants ?
(Have done this on a few other networks but with Cisco Sg300 switches, with no problems at all)

regards

Søren

[MilesMeraki]

I don't see why this wouldn't be possible as long as your STP design supported this topology. I.e MS320 (A1) as the root bridge and port costs, speed links etc would ensure that the STP topology would match your intended design. I.e The Meraki switches would just put the "highest cost" ports to the root bridge in a discarding state until a change in the topology was noticed. Meraki switches support STP/RSTP.

What other branded switches are you using for C2 and D2, do these support STP/RSTP and what speeds are the ports on these switches?

It would be great to also know what interfaces/ports on the switches that you would use for the re-redundant and primary links for each switch.

[Søren_Steinmetz]

Thanks for the reply, I have tried to pin out the setup a bit more.

Present setup:
switch-port:
A1-25 SFP - D1-10 SFP backbone
A1-26 SFP - C1-10 SFP backbone
A1-27 SFP - B1-24 SFP backbone
A1-28 SFP - B2-24 SFP backbone

C1-8 Cat6 - C2-8 Cat6

D1-8 Cat6 - D2-8 Cat6

Redundant setup by adding:
switch-port:
B1-23 SFP - B2-23 SFP (or just using Cat6 as they are mounted in the same rack)

B1-22 SFP - C1-9 SFP (or C2-9 SFP if it supports stp/rstp proper)

B2-22 SFP - D1-9 SFP (or D2-9 SFP if it supports stp/rstp proper)

B1-21 + B2-21 SFP's are kept as spare for now, or get fiber to the ESXi host in that rack 😉

The STP are set up with:
A1 as 0-root
B1 - 4096
B2 - 8192
D1 - 12288
C1 - 24576
RSTP enabled

All switches are 1Gb except the 10Gb SFP+ on the MS320
A1 - MS320-24P
B1 + B2 - MS220-24P
C1 + D1 - MS220-8P

C2 is a D-Link DGS-1210-10P only used for two printers and a single workstation

D2 is a D-link DGS-1210-10P only used for 5 dockingstations if the teachers need cable and a bigger monitor

Not sure if I need to learn a bit about OSPF to get it to work though.

regards

Søren

[Chris_M · Accepted solution]

Your current setup looks great.

You may need to configure the DLINK to support RSTP, depending on your hardware version, the newest one enables MSTP by default but RSTP is off. VLAN tagging is off as well.

You don't need OSPF to create redundant links, unless each segment is it own IP subnet, which I doubt you are doing.

[Søren_Steinmetz]

Thanks Chris

The main part of the network are the Meraki switches, the two D-Link (and a third in my office) are not "mission critical" so they get redundant if I feel like it, if not then no big deal.

Was just curious if I was wrong about the possibility to create redundant setup like the one I wanted, makes me happy to see I was on the right track.

And yes, all switches are on the same IP subnet.

[PhilipDAth]

This is the Meraki campus design guide.

https://meraki.cisco.com/lib/pdf/meraki_campus_deployment_guide.pdf

On the whole, I would change your design.  You don't want links between access blocks.  Given you diagram, you are probably best having a collapsed core-distribution switch (or switch stack for redundancy).  You should then dual connect each access block to the collapsed core.

[Søren_Steinmetz]

In the perfect setup yes, but what I have to work with now is the best we could afford.

Even getting a MS320 as core instead of "just" another MS220 was taxing the budget.

At the time I had the choise to get this setup, get a setup based entirely on Cisco SG300 series or a setup based entirely on D-Link.

 (The two D-Link had to be added later as we changed the workspace for the teachers ahead of scheduled expansion, I plan to get them changed to Meraki as well)

The way the net is build all switches are dual role as both access and core switches, at least the three larger ones (A1, B1 and B2)