Port Mirroring as an uplink cross-connect?

[Gateway-SF]

Hi, I have a how-to question that I need to verify will work as expected, or ask for a workable solution:

We are a 100% Meraki network. We have an MDF and IDF with a fiber crossover. I'm having a WISP backup internet service activated that is near the IDF (the receiver is already there and the MDF is much harder to reach). The WISP handoff is a CAT5e RJ45 male that I'd plug into a port on an MS320 switch in the IDF. Will setting up Port Mirroring on the MS320 switch with an ethernet port that mirrors traffic to a fiber port on the same switch work in delivering the WISP's uplink over a separate fiber strand to the MDF ? That fiber crossover cable would then be plugged into our MX250's WAN-2 port, and I'd set up failover. Would port mirroring work in this application? Would port isolation be necessary or usable for both the source and destination ports?

If this isn't the correct application for port mirroring, how would you recommend I get the WISP uplink from an MS switch in our IDF to the MX250 uplink port in our MDF?

Thank you!

[mwiater · Accepted solution]

I'd think this might be a good use for a dedicated VLAN on those two ports and the MX.

[PhilipDAth]

As @mwiater mentions, you would use a plain old ordinary VLAN for this, not port mirroring.

[Brash]

Port mirroring is typically used for troubleshooting, or special traffic conditions (eg voice recorders for VOIP).

It would not be a good idea to use this for the purposes you're describing. Instead, as suggested above you should be able to achieve your outcome by simply tagging the WISP uplink traffic onto an unused vlan to send it across the fiber to the MX WAN port - Both the WISP cat5 port and the fiber port going to the MX tagged as access ports.

With that said, the best option is to have the ISP run the to MDF instead.