Campus lan and Wireless lan solution Design Guide

 
Single building with more than 400 APs 
Figure 32. 
● 
If the deployment has a roaming domain that spans across multiple buildings, with more than 400 APs, 
consider configuring a Site Tag per building.
 
Multiple buildings with more than 400 APs 
Figure 33. 

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Page 46 of 76
● 
If the deployment has multiple buildings, with less than 400 APs, consider configuring a single custom site 
tag. Don't use the default site tag. 
 
Multiple buildings with less than 400 APs 
Figure 34. 
● 
When deploying Cisco FlexConnect, set the site tag to be a non-Local Site within the Cisco Catalyst 9800 
configuration. When the Local Site option is disabled, the site tag is equivalent to a Cisco FlexConnect 
Group in classic Cisco AireOS wireless controllers. 
 
Site Tags for Cisco FlexConnect APs 
Figure 35. 
There is a limit of 100 APs per Cisco FlexConnect site tag for seamless roaming. Roaming across site tags for 
Cisco FlexConnect APs results in a client full reauthentication.
High availability 
As more devices with critical functions move to the wireless medium, high availability of the wireless 
infrastructure is becoming increasingly important. Real-time audio, video, and text communication relies on the 
corporate wireless network, and the expectation of zero downtime is becoming the norm. The negative impacts 

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of wireless network outages are just as impactful as outages of the wired network. Implementing high availability 
within the wireless infrastructure involves multiple components and functionality deployed throughout the overall 
network infrastructure, which itself must be designed for high availability. This section discusses high availability 
specific to the implementation of wireless controller platforms. Platform-level redundancy refers to the ability to 
maintain wireless service when connectivity to one or more physical WLAN controller platforms within a site is 
lost.
Designing for high availability must also consider the entire lifecycle of the deployment, including the need for 
updates and upgrades on the network. This section also discusses the use of software maintenance updates 
(SMUs) for wireless controller fixes and updates, AP service packs (APSPs) for AP fixes and updates, and AP 
device packs for support for new AP models
The methods of high availability discussed within this design guide, available with releases of Cisco IOS-XE 17.1 
and higher, are as follows: 
● 
High availability SSO 
● 
N+1 high availability 
● 
WLAN controller link aggregation 
● 
Wireless controller patches using software maintenance updates (SMUs) 
● 
AP patches using AP service packs (APSPs) 
● 
Support for new AP models using AP device packs (APDPs)