Multi-Site SD-Access Wireless

[fatalXerror]

Hi Guys,

New in SD, I have a multi-site SD-Access Wireless and I would like to ask the following,

1. Can I stretch my staff wireless network from site A to site B so that I can only use one IP subnet for my staff wireless? I want that if a user goes to site B and connect to the staff wireless, the IP address should be the same as in site A.

2. If item number 1 is possible, is it required to have a WLC per site?

3. What can I achieve if I only have a pair of WLC in site A and only APs in site B?

4. What can I achieve if I have 2 sets WLCs per site?

Thank you

[jedolphi]

Hello! A1- Yes, there is a 3-part video series on Multisite Remote Border, https://youtu.be/w5HQ_CrcxuU . A2- Yes. A3- Not SD-Access Fabric Enabled Wireless. 4- One WLC per site is enough to have both local subnets and anchored subnets, check out the video series and then ask more questions if you need. Cheers, Jerome

[fatalXerror]

Hi @jedolphi ,

For your answer for my Q3, what do you mean by "Not Fabric Enabled Wireless"? What is the difference if the WLC is deployed as Fabric-Enabled versus non-Fabric Enabled?

Thank you

[jedolphi]

Hi, I mean not a wireless solution that is integrated with SD-Access - Fabric-Enabled Wireless is heavily integrated to the SD-Access policy/data/control planes. Maybe it could be some traditional wireless implementation e.g. centrally switched wireless. I am by no means a traditional wireless SME though, so please refer to traditional wireless design best practices. For Flex WiFi with SD-Access we have some limited support now with more to come later. For SD-Access + Flex WiFi please talk to your AM or SE. Note that Fabric-Enabled Wireless is the recommended approach if possible because if the tight integration with the wired SD-Access Fabric.

[fatalXerror]

Hi @jedolphi , 

thanks for the help.

Just a follow up question, so if I have only a pair of WLC in my site A and only APs in site B, will the traffic goes to its local internet or it will be backhauled to the site A where the WLC is located?

Thank you

[jedolphi]

Hello, in that scenario Fabric-Enabled Wireless (the recommended solution) is not supported. At this stage FEW needs the WLC to be at the same Fabric Site as the APs (please also note we have embedded WLC in catalyst 9000 switch as an option for SD-Access, for smaller sites, if that helps you). If you proceed with the design proposed then you'll need to use a traditional wireless solution, either Flex or Central Switching. Flex has limitations when used in conjunction with SD-Access switching and you'll need to talk to your SE/AM/CX contact to discuss the specifics. Centrally switched wireless traffic would be tunneled back to the WLC, but please check with a wireless SME on the caveats of multisite centrally switched wireless because in this case the wireless implementation is unrelated to SD-Access, it's just using SD-Access switch as a transit from AP to WLC.

[fatalXerror]

Hi @jedolphi , I see so even in SDA Wireless, the concept of centrally switching in WLC will still takes place am I correct? If this is the case, if I have pair of WLCs per site, can I still do the stretched wireless VN so that I will only have the same client IP pool whenever I go? Thank you so much, you are a big help.

[jedolphi]

Hi. Fabric-Enabled Wireless (aka SD-Access Wireless) is a discrete wireless mode. In other words we have three possible modes 1. FEW, 2. Flex, 3. Centrally Switched. FEW is somewhat like Flex, not like Central Switching. There's a Cisco Live presentation that unpacks FEW if you're interested, it's a little older but the fundamentals haven't changed, https://www.ciscolive.com/on-demand/on-demand-details.html?#/session/16360600412110017JEn . There's no way to have FEW if there's not WLCs at each Fabric Site. The best practice recommendation is to use FEW which requires a WLC at each site, you could consider Embedded WLC which is free and does not require extra hardware, but has switching platform requirements and scaling limits. If you must go with a non-FEW solution then traditional WiFi design rules apply and you'll need to consult with a traditional wireless SME please, traditional wireless is not my area of expertise and would not be in scope for the SD-Access community forum.