Connect 2 MS355-48X2 Switches with QSFP+ Cable?

[amwjoe]

We are working on implementing 2 MS355-48X2 servers in our Datacenter soon and slipped my mind about the QSFP+ ports on these.

These switches will have their own uplink to our FortiGate firewalls and servers will have NIC1 going to SW1 and NIC2 going to SW2 on the 2 MS355's. I won't be stacking these to avoid downtime during firmware upgrades but should I use the QSFP+ so that connectivity between the 2 switches will be able to take advantage of the 40GB speeds?

[alemabrahao]

It's not that you should, if you think it makes sense I don't see a problem. If it's something you have available and it won't generate any additional costs, go ahead.

[amwjoe]

Thanks - I probably need to rephrase my question.

Will I see performance benefits by using the QSFP+ between these 2 switches? 

[alemabrahao · Accepted solution]

I particularly see the benefit if you have traffic that justifies this speed. If not, I see it as unnecessary, but as I said, if it won't generate any additional costs there's no problem, especially because I believe that having a guaranteed higher speed is not a problem, correct?

[cmr]

If you aggregate the two QSFP+ ports then you have a highly available 80Gbps inter-switch link, sounds good to me.

[amwjoe]

Thank you both. I'll put 1 maybe 2 for a highly available inter-switch link. Assuming I wouldn't have issues with setting up 2?

Another question while on this - I'm assuming when I use a QSFP+ port, it'll disable the uplink on one of the switches to my Fortigate. For example: If SW1's QSFP+ becomes the uplink to SW2 and when I do a firmware update or reboot on SW1, will SW2 connections notice any interruptions? 

[alemabrahao]

In theory, if you have redundancy in Uplinks, there is no reason to have any kind of unavailability.

Do you have a network topology just to check that all your connections are redundant?

[amwjoe]

Here's what we'd be looking to setup (arrow for the QSFP+ can be disregarded but just representing the link). I'm more so referring to the time between it takes to release the QSFP+ as the uplink and failover to its individual uplink. 

[alemabrahao]

Prefect, if whatever is below the switches has a connection to each one of them, I believe it is enough to not have unavailability in the case of scheduled maintenance.