Cisco SDA Design - Wireless P2P Bridge

[Marco111]

Hi Everyone, I'm currently in middle of a rollout of Cisco SDA across our estate incorporating Cisco DNA Center, ISE, ACI etc. Its going well :). Most of my sites are either private fiber or leased circuits which have been migrated to Cisco without an issue. Most are small so all setup as FIAB connecting back via the private fibre / Leased line to the Fusion Node (Backbone Router). I do however have some sites that connect via Wireless P2P bridges these all terminate currently onto a Layer 2 switch acting as a media convertor so basically just passing the VLANs up to the backbone router for connectivity. Below (Diagram A) shows current setup will I be able to keep the layer 2 switch acting as a media convertor in place and just pass all the required underlay/overlay VLANs from each sites FIAB through it back to the Fusion Router for handoff or will this not work? My other thought (Diagram B) is to swapout the layer 2 switch for something like a C9500 and set it up as a another Fusion router so each link can directly handoff from the FIAB on each site.. i guess another possibility (Diagram C) is to setup a C9500 as the BN/CP with each connecting Edge setup within a fabric zone for each site.. any best practice recommendations would be great. Thanks

Diagram A

Diagram A

Diagram B

Diagram B

Diagram C

Diagram C

[andy!doesnt!like!uucp]

Cisco CX services labbed diagram 3 as a PoC in our account. In the lab it's single connection though.
All options are liveable. It's for u to decide by considering all cons&pros

[jedolphi]

Routing generally better than switching, but you can keep the "Layer 2 Switch Media Converter" if you must. SDA overlay does not care what the underlay platforms and technologies (e.g. wifi bridge) are, as long as the underlay meets the fundamental SDA overlay requirements. This means transport MTU needs to solve for potentially large VXLAN with DF bit set, and PIM/multicast might be needed in underlay for overlay layer 2 flooding and/or native multicast routing. So will it work? Answer: maybe, it depends on capabilities of the wifi bridging devices and the overlay MTU and multicast requirements, which in turn depends on how the overlays are configured (L2F, native/HER multicast routing, adjust MSS, PMTUD, etc). That said, yes other people have done this successfully, noting that the particular design details matter, cannot give a rubber stamp without understanding the specifics. Best regards, Jerome

[Marco111]

Thanks @jedolphi @andy!doesnt!like!uucp  for your comments and advice, its appreciated. Some of the wireless bridges are dated (Motorola 54500)so a bit of a concern as features and configurable options are limited, but I do have the facilities to fully test before putting into production, will put together a test initially using the switch acting as media convertor first to test if that will work. Then take it from there. Thanks again.