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Arista Cognitive Wi-Fi Integration with Purple WiFi

This technical reference details the step-by-step integration of Arista Cognitive Wi-Fi (CV-CUE) with Purple's guest WiFi platform for enterprise venues. It covers Arista captive portal configuration, Walled Garden ACL design, RADIUS server setup, secure staff 802.1X authentication, and Multi-Tenant isolation using Arista PPSK with dynamic VLAN steering - giving IT teams and network architects a definitive deployment blueprint.

📖 10 min read📝 2,486 words🔧 3 worked examples3 practice questions📚 10 key definitions

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Welcome to the briefing. Today, we are dissecting the integration of Arista Cognitive Wi-Fi with the Purple platform. This is a senior consultant briefing, aimed squarely at enterprise network architects and cloud systems administrators who need to get this deployed correctly, the first time. Let us set the scene. Arista Cognitive Wi-Fi, managed through the CloudVision Cognitive Unified Edge platform, is a cloud-managed wireless infrastructure that supports enterprise-grade guest and staff network deployments. Purple is a hardware-agnostic cloud overlay that provides the guest portal, identity capture, RADIUS authentication, and analytics layer. When you combine the two, you get a complete, compliant, and commercially valuable guest WiFi architecture. Let us get into the mechanics. The first thing to understand is the captive portal onboarding flow. When a guest device associates with the open guest SSID on an Arista access point, the AP immediately places that device into a pre-authentication VLAN. In this state, the device has a DHCP-assigned IP address, but its DNS and HTTP traffic is heavily restricted. The device operating system, whether iOS, Android, or Windows, performs a captive portal detection probe. iOS sends an HTTP request to captive.apple.com. Android probes connectivitycheck.gstatic.com. The Arista AP intercepts this request and returns a 302 redirect, pointing the device to the Purple splash page URL. Now, this is where most deployments go wrong. For that redirect to work, and for the splash page to actually render, you need to configure the Walled Garden correctly in Arista CV-CUE. The Walled Garden is an explicit allow-list. In the pre-authentication state, all traffic is dropped by default. You must whitelist every domain required to load the portal. At minimum, that means the core Purple domains: region1.purpleportal.net, venuewifi.com, and cloudfront.net. If you are offering social login via Google Workspace, you must add accounts.google.com and its associated CDN ranges. For Facebook, you need facebook.com, fbcdn.net, and akamaihd.net. Miss any one of these, and the guest sees a blank screen or a spinning login button. They walk away, and you lose the data capture opportunity. Let me walk you through the RADIUS configuration in CV-CUE. Navigate to Configure, then Network Profiles, then RADIUS. Click Add RADIUS Server. Enter the Purple primary RADIUS server IP address, set the Authentication Port to 1812, the Accounting Port to 1813, and enter the shared secret provided by Purple. Repeat this for the secondary server. This redundancy is critical. If the primary server is unreachable, the secondary takes over without interrupting guest access. Once the RADIUS profiles are saved, go to Configure, then WiFi, then SSID, and click Add New SSID. Name your SSID, set the type to Guest, and under the Security tab, set the security level to Open. This is correct for a captive portal deployment. Under the Captive Portal tab, enable the Captive Portal checkbox, select Third-Party Hosted from the Cloud Hosted drop-down, and check the With RADIUS Authentication box. Paste the Purple Splash Page URL into the Splash Page URL field. This is typically in the format https://region1.purpleportal.net/access/. Enter the shared secret. Then, in the Websites that users can access before login section, add your Walled Garden domains. Set the Called Station ID format to percent-m, which sends the MAC address in the format Purple expects. Set the Accounting Interval to 2 minutes. Clear the HTTPS Redirection checkbox. Save the SSID. It will propagate to your Arista APs within minutes. Now let us talk about what happens after the guest submits their details on the Purple portal. Purple acts as the RADIUS server. It validates the identity, captures the consent, and sends a RADIUS Access-Accept message back to the Arista AP. But here is the critical piece: that Access-Accept message contains Change of Authorization attributes, defined in RFC 3576. These attributes instruct the Arista AP to dynamically transition that specific client from the restricted pre-authentication state to the post-authentication VLAN with full internet access. Simultaneously, the AP sends a RADIUS Accounting-Start message to Purple on port 1813. This starts the session timer and feeds session duration data into the Purple analytics dashboard. Let us move to the more advanced use case: Multi-Tenant WiFi using Arista Private Pre-Shared Keys, or PPSK. This is the architecture you want for coworking spaces, retail malls, residential buildings, or any environment where you have multiple distinct user groups that need strict network isolation. The problem with traditional approaches is that broadcasting a separate SSID for each tenant creates massive RF overhead. Every SSID requires beacon frames. In a dense environment with 20 tenants, that is 20 SSIDs consuming airtime. PPSK solves this elegantly. You broadcast a single SSID. But in the Purple portal, each tenant is assigned a unique passphrase. When a user connects, the Arista AP authenticates that passphrase against the Purple RADIUS server. Purple looks up the passphrase, identifies the associated tenant, and returns an Access-Accept message. But critically, it appends three RADIUS attributes: Tunnel-Type, set to VLAN; Tunnel-Medium-Type, set to 802; and Tunnel-Private-Group-ID, set to the tenant's specific VLAN ID. The Arista AP reads these attributes and dynamically steers the client to the correct VLAN. Tenant A, using their passphrase, lands on VLAN 100. Tenant B lands on VLAN 200. They are completely isolated at Layer 2. They cannot see each other's devices, printers, or servers. This is Identity-Based Networking in practice. The identity of the passphrase determines the network segment. It is centrally managed through Purple, so when a tenant leaves, you revoke their passphrase in the Purple portal, and access is immediately terminated. No changes required on the Arista infrastructure. Now, let us cover Secure Staff WiFi using IEEE 802.1X. For your staff SSID, you should not be using a shared passphrase. You should be using 802.1X with EAP, Extensible Authentication Protocol. In CV-CUE, create a new Corporate SSID. Under the Security tab, select WPA2-Enterprise or WPA3-Enterprise. Select your RADIUS profile, which should point to your corporate identity provider, such as Microsoft Entra ID or Okta. When a staff member connects, their device presents credentials to the Arista AP, which forwards them to the RADIUS server via EAP. The identity provider validates the credentials and returns an Access-Accept. For certificate-based authentication using EAP-TLS, the device presents a client certificate rather than a username and password, eliminating credential theft as an attack vector entirely. Let me address the Arista Cloud WIPS integration. Arista's Wireless Intrusion Prevention System operates in the background, scanning for rogue access points and unauthorized clients. In CV-CUE, navigate to Configure, then WIPS, then Automatic Intrusion Prevention. You can configure the prevention level from Degrade through to Block. For enterprise deployments, we recommend the Disrupt level as a starting point, which disrupts unauthorized communication without completely blocking it, reducing false positive risk. You should also configure VLAN monitoring under Configure, then Device, then Access Point, selecting the Security tab. Enable SSID VLAN Monitoring so that APs actively monitor their assigned VLANs for rogue activity. Now, a few implementation pitfalls to avoid. First, DHCP pool exhaustion. In high-footfall environments like retail stores or stadiums, devices connect briefly and walk away. If your idle timeout is set too high, those sessions remain active, holding IP addresses. Set the idle timeout in CV-CUE to 10 minutes for retail, and as low as 5 minutes for event venues. This aggressively reclaims IPs and prevents the pool from exhausting. Second, MAC address randomization. Since iOS 14 and Android 10, devices randomize their MAC address per SSID by default. This breaks any architecture that relies on MAC addresses to identify returning guests. The correct response is to shift your identity model to authenticated credentials, the email address or social login captured through the Purple portal. For seamless reconnection without a portal, the long-term migration path is to Passpoint, also known as Hotspot 2.0, which uses certificate-based authentication and eliminates the captive portal entirely. Third, HTTPS redirection. When configuring the captive portal in CV-CUE, ensure the HTTPS Redirection checkbox is cleared. Purple handles the HTTPS session independently. Enabling HTTPS redirection on the Arista side can cause certificate mismatch errors that prevent the portal from loading. Let us do a rapid-fire question and answer on common scenarios. Question: A guest's portal page shows a blank screen. Where do you look first? Answer: The Walled Garden. A missing domain is almost always the cause. Check that all Purple domains and the relevant Identity Provider CDN domains are whitelisted in CV-CUE. Question: PPSK users are all landing on the default VLAN. What is wrong? Answer: The Purple RADIUS server is not returning the Tunnel-Private-Group-ID attribute. Check the RADIUS response in the CV-CUE troubleshooting logs and verify the VLAN mapping in the Purple portal. Question: The RADIUS accounting data in Purple is showing sessions of zero seconds. What is the issue? Answer: The Accounting Port is likely misconfigured or blocked. Verify that port 1813 is open on the firewall between the Arista APs and the Purple RADIUS servers, and that the accounting interval is set to 2 minutes in the SSID settings. To summarise the key takeaways from this briefing. One: the Walled Garden is an explicit allow-list. Maintain it as a recurring operational task, not a one-time setup. Two: RADIUS Change of Authorization is the mechanism that grants access. Without it, the portal completes but the guest remains blocked. Three: Arista PPSK with Purple RADIUS enables dynamic VLAN steering for multi-tenant isolation on a single SSID, eliminating beacon overhead. Four: always enable Client Isolation on Guest SSIDs to prevent lateral movement. Five: MAC address randomization requires a shift to identity-based authentication for accurate analytics. Six: proper integration satisfies GDPR consent requirements and captures first-party data that directly drives marketing ROI. Your next steps: retrieve the Purple RADIUS server IP addresses and shared secrets from the Purple portal hardware configuration page. Configure the RADIUS profiles in CV-CUE. Build your Walled Garden domain list. Deploy your Guest SSID. Test the full authentication flow from a mobile device before rolling out to production. And if you are deploying multi-tenant environments, map your tenant VLAN IDs in Purple before configuring the PPSK passphrases. That concludes this technical briefing. Thank you for listening.

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Executive summary

Deploying an Arista captive portal for guest access is not merely a connectivity task. It is a critical intersection of network security, regulatory compliance, and data strategy. For IT leaders managing distributed venues, the integration of Arista CloudVision Cognitive Unified Edge (CV-CUE) with Purple transforms unmanaged guest traffic into a secure, segmented, and measurable asset.

This reference provides a definitive blueprint for configuring Arista Cognitive Wi-Fi with Purple. We detail the exact mechanisms required to deploy third-party hosted splash pages, construct precise Walled Garden access control lists, and implement RADIUS authentication. We also cover advanced Multi-Tenant WiFi isolation using Arista Private Pre-Shared Keys (PPSK) and dynamic VLAN steering - the architecture that eliminates SSID sprawl in coworking spaces, retail malls, and residential buildings.

Purple operates across 80,000+ live venues and has processed 440 million logins in 2024 (Purple internal data). The platform is ISO 27001 certified, GDPR and CCPA compliant, and carries Cyber Essentials and B Corp certification. This guide reflects production-tested configurations validated across hospitality, retail, and public-sector deployments.


Technical deep-dive

The Arista captive portal onboarding architecture

The guest onboarding flow dictates how devices interact with the Arista access point (AP) before and after authentication. When a device associates with the open guest SSID, the Arista AP assigns it to a pre-authentication VLAN. In this state, the AP restricts DNS and HTTP traffic to a defined allow-list. The device operating system detects the captive portal and attempts to reach a known endpoint - iOS sends an HTTP request to captive.apple.com, Android to connectivitycheck.gstatic.com, and Windows to www.msftconnecttest.com. The Arista AP intercepts this request and issues an HTTP 302 redirect to the Purple splash page URL.

{{asset:captive_portal_flow.png}}

To ensure this flow executes without error, the Arista CV-CUE controller must be configured to point to Purple as a third-party hosted portal. This requires defining the Purple RADIUS servers (Authentication Port 1812, Accounting Port 1813) within the CV-CUE Network Profiles. Once the guest submits their credentials or accepts the terms on the Purple portal, Purple acts as the RADIUS server and sends an Access-Accept message back to the Arista AP. This message includes RADIUS Change of Authorization (CoA) attributes defined in RFC 3576, instructing the AP to transition the client MAC address from the restricted pre-authentication state to full internet access on the post-authentication VLAN.

architecture_overview.png

Walled Garden ACL design in CV-CUE

The Walled Garden is a whitelist of domains and IP addresses that unauthenticated devices must reach to load the splash page and complete authentication. In Arista CV-CUE, you configure this under the Captive Portal settings as "Websites that users can access before login".

The Walled Garden is an explicit allow-list. You must include the core Purple domains to render the portal. If you offer social login, you must also whitelist the Identity Provider (IdP) domains. Failure to maintain this list results in guests being unable to load the authentication provider's login screen, leading to immediate abandonment.

Zone Traffic permitted Implementation
Pre-authentication DNS (restricted), DHCP, portal server, captive portal detection endpoints Gateway ACL - deny all except whitelist
Walled Garden Purple portal domains, social login providers, payment processors FQDN-based ACL in CV-CUE
Post-authentication Full internet access subject to content filtering and bandwidth policy Per-user ACL applied via RADIUS CoA

Minimum required Walled Garden entries for Purple:

  • region1.purpleportal.net
  • venuewifi.com
  • cloudfront.net
  • openweathermap.org
  • stripe.com (if payment-gated access is enabled)

Additional entries for social login:

  • Facebook: facebook.com, fbcdn.net, akamaihd.net, connect.facebook.net
  • Google Workspace: accounts.google.com, googleapis.com
  • Twitter/X: twitter.com, twimg.com
  • LinkedIn: linkedin.com, licdn.net

Arista PPSK configuration for multi-tenant isolation

For environments such as coworking spaces, residential buildings, or retail malls, standard 802.1X is often too complex for unmanaged devices, yet open networks lack necessary security. Arista Private Pre-Shared Keys (PPSK) solves this by allowing multiple unique passphrases on a single SSID, each mapped to a distinct network policy.

ppsk_vlan_diagram.png

When integrated with Purple RADIUS, Arista PPSK enables dynamic VLAN steering. A resident or retail tenant connects to the unified SSID using their specific PPSK. The Arista AP authenticates the key against the Purple RADIUS server. Purple returns the standard Access-Accept, but appends three RADIUS attributes that drive VLAN assignment:

RADIUS attribute Value Purpose
Tunnel-Type 13 (VLAN) Specifies the tunnel type
Tunnel-Medium-Type 6 (802) Specifies the medium type
Tunnel-Private-Group-ID e.g., "100" The specific VLAN ID to assign

The Arista AP dynamically assigns the device to that VLAN. This provides strict Layer 2 isolation between tenants without broadcasting dozens of separate SSIDs, optimising RF utilisation while maintaining absolute security boundaries.

Secure Staff WiFi with IEEE 802.1X

For staff networks, shared passphrases are a security liability. IEEE 802.1X (defined in IEEE Std 802.1X-2020) provides port-based network access control using per-user credentials. In CV-CUE, you configure a Corporate SSID with WPA2-Enterprise or WPA3-Enterprise security. The AP acts as the authenticator, forwarding credentials to the RADIUS server via EAP (Extensible Authentication Protocol). Purple supports EAP-PEAP for username/password authentication and EAP-TLS for certificate-based authentication.

For EAP-TLS deployments, you integrate with Microsoft Entra ID, Okta, or Google Workspace as the certificate authority. When a staff member's device presents a valid client certificate, the RADIUS server validates it against the directory and returns an Access-Accept. This eliminates credential theft as an attack vector entirely.

Arista Cloud WIPS integration

Arista's Wireless Intrusion Prevention System (WIPS) operates continuously in the background, scanning for rogue access points, misconfigured APs, and unauthorized clients. In CV-CUE, navigate to Configure > WIPS > Automatic Intrusion Prevention to configure the prevention level. Arista offers four levels: Degrade, Interrupt, Disrupt, and Block. For enterprise deployments, start at Disrupt, which disrupts unauthorized communication without completely blocking it, reducing false positive risk during initial deployment.

Enable SSID VLAN Monitoring under Configure > Device > Access Point > Security tab to ensure APs actively monitor their assigned VLANs for rogue activity. Arista AP-3xx series models support monitoring up to 42 VLANs simultaneously (Arista WIPS documentation, 2025).


Implementation guide

Phase 1: Network segmentation and RADIUS setup

  1. Log in to Arista CV-CUE and navigate to Configure > Network Profiles > RADIUS.
  2. Click Add RADIUS Server.
  3. Enter the Primary Purple RADIUS server details: IP Address, Authentication Port (1812), Accounting Port (1813), and the Shared Secret from the Purple portal hardware configuration page.
  4. Repeat for the Secondary Purple RADIUS server to ensure high availability.
  5. Verify that UDP ports 1812 and 1813 are open between the Arista APs and the Purple RADIUS servers on your firewall.

Phase 2: Guest SSID and captive portal configuration

  1. Navigate to Configure > WiFi > SSID and click Add New SSID.
  2. Define the SSID Name (e.g., Guest_WiFi) and set the SSID Type to Guest.
  3. Under the Security tab, set the security level to Open.
  4. Under the Network tab, configure the pre-authentication VLAN (e.g., VLAN 10) with a dedicated DHCP scope.
  5. Under the Captive Portal tab, enable the Captive Portal checkbox.
  6. Select Third-Party Hosted from the Cloud Hosted drop-down.
  7. Check With RADIUS Authentication and select the Purple RADIUS profile.
  8. Enter the Purple Splash Page URL (e.g., https://region1.purpleportal.net/access/) and the Redirect URL (e.g., https://region1.purpleportal.net/access/?res=success).
  9. Set the Called Station ID format to %m (MAC address format required by Purple).
  10. Set the Accounting Interval to 2 minutes.
  11. Clear the HTTPS Redirection checkbox.

Phase 3: Walled Garden deployment

  1. Within the Captive Portal tab, locate the Websites that users can access before login section.
  2. Add all required Purple domains and Identity Provider domains as listed above.
  3. Save the SSID configuration and apply it to the target Arista AP groups.

Phase 4: PPSK multi-tenant setup

  1. In the Purple portal, navigate to the venue hardware configuration and retrieve the PPSK RADIUS settings.
  2. In CV-CUE, create a new SSID with WPA2-Personal security and enable PPSK mode.
  3. Configure the SSID to authenticate against the Purple RADIUS profile.
  4. In the Purple portal, create a PPSK passphrase for each tenant and map it to the corresponding VLAN ID.
  5. Verify that the switch ports connecting to Arista APs are configured to trunk the required tenant VLANs.

Phase 5: Secure Staff WiFi (802.1X)

  1. Create a new Corporate SSID in CV-CUE.
  2. Under the Security tab, select WPA2-Enterprise or WPA3-Enterprise.
  3. Select the RADIUS profile pointing to your corporate identity provider (Microsoft Entra ID, Okta, or Google Workspace).
  4. Configure EAP type: PEAP for username/password, EAP-TLS for certificate-based authentication.
  5. Assign the Staff SSID to a dedicated VLAN (e.g., VLAN 20) isolated from the Guest VLAN.

Best practices

Automate Walled Garden updates. Identity providers frequently change their CDN domains. Schedule a quarterly review of your Arista CV-CUE Walled Garden configuration against Purple's updated domain lists. A single missing CDN entry will break social login for all guests.

Optimise session timers by venue type. Configure idle timeouts in Arista CV-CUE to match your venue's traffic profile. Retail environments benefit from a 10-minute idle timeout to reclaim IP addresses from devices that have left the store. Hotel deployments should use longer timeouts (4-8 hours) to avoid re-triggering the portal during a guest's stay.

Enforce Client Isolation. Always enable Client Isolation on the Guest SSID within Arista CV-CUE. This prevents guest devices from communicating with each other, mitigating lateral movement risks and satisfying PCI DSS network segmentation requirements.

Enable RADIUS Accounting. Ensure RADIUS Accounting is enabled with a 2-minute interval. This provides Purple with accurate session duration and data transfer metrics, feeding into the WiFi Analytics dashboard and enabling accurate visitor dwell time analysis.

Segment by SSID type, not by AP. Apply Guest, Staff, and Multi-Tenant SSIDs to the same AP groups. Arista CV-CUE handles VLAN tagging per SSID, so you do not need separate APs for each user type. This simplifies your hardware deployment while maintaining strict logical separation.

For a broader view of enterprise WiFi security architecture, see our Enterprise WiFi Security: A Complete Guide for 2026 .


Case studies

Case study 1: 350-room hotel chain

A mid-scale hotel chain with 12 properties deployed Arista Wi-Fi 6E APs across all sites, managed through a single CV-CUE instance. The requirement was to provide branded Guest WiFi with email capture for marketing, isolated from the property management system (PMS) network, while also supporting 802.1X for staff devices.

The team configured three SSIDs per property: a Guest SSID (VLAN 10) pointing to Purple, a Staff SSID (VLAN 20) using 802.1X against Microsoft Entra ID, and an IoT SSID (VLAN 30) for building management devices. The Purple portal captured guest email addresses and consent at check-in. Within 90 days, the chain had collected verified first-party data from 68% of guests (Purple internal data), enabling targeted re-engagement campaigns. The PMS network remained completely isolated, satisfying PCI DSS requirements for cardholder data environment segmentation.

Case study 2: Multi-tenant coworking space

A coworking operator managing eight locations needed to provide isolated WiFi to 35 member companies per site without broadcasting 35 SSIDs. The RF environment was already congested, and SSID sprawl was degrading performance for all members.

The solution was a single SSID per site using Arista PPSK with Purple RADIUS. Each member company received a unique PPSK passphrase. Purple mapped each passphrase to a dedicated VLAN (VLAN 100 through VLAN 3500). When a member connected, the Arista AP dynamically steered them to their VLAN based on the Tunnel-Private-Group-ID returned by Purple RADIUS. The result was a reduction from 35 SSIDs to one per site, a measurable improvement in airtime efficiency, and complete Layer 2 isolation between member companies. When a member's contract ended, the operator revoked their passphrase in the Purple portal, terminating access within seconds.


Troubleshooting and risk mitigation

Issue: Splash page fails to load on Apple devices. iOS uses a specific mechanism to detect captive portals. If the splash page fails to load automatically, verify that the Arista Walled Garden includes all Purple CDN domains. If the Walled Garden is overly restrictive, the iOS device cannot load the portal assets and aborts the connection.

Issue: MAC address randomization breaks returning guest recognition. iOS 14+ and Android 10+ devices randomize their MAC address per SSID. This prevents Purple from recognizing a returning guest based solely on their MAC address. Rely on authenticated identity (email or social login) for long-term tracking. For seamless, secure reconnection without a captive portal, migrate to Passpoint/Hotspot 2.0 architectures.

Issue: Dynamic VLAN steering fails with PPSK. If tenants are assigned the default VLAN instead of their specific VLAN, verify the RADIUS response using the Arista CV-CUE troubleshooting tools. Ensure Purple is returning the correct Tunnel-Private-Group-ID, Tunnel-Type, and Tunnel-Medium-Type attributes, and that the specified VLAN exists on the switch port connected to the Arista AP.

Issue: DHCP pool exhaustion on the Guest VLAN. Reduce the idle timeout to 5-10 minutes in high-footfall environments. Increase the DHCP scope size if the venue regularly exceeds 80% pool utilisation. Consider using a /22 or larger subnet for high-density venues such as stadiums or conference centres.

Issue: RADIUS accounting data shows zero-second sessions. Verify that UDP port 1813 is open on the firewall between the Arista APs and the Purple RADIUS servers. Confirm the Accounting Interval is set to 2 minutes in the CV-CUE SSID settings.

For related guidance on wireless display and protocol best practices in enterprise environments, see What Is Wireless Display: Protocols and Best Practices 2026 .


ROI and business impact

Deploying Arista Cognitive Wi-Fi with Purple transforms a network cost center into a measurable business asset. By enforcing a compliant captive portal, you mitigate the risk of GDPR fines, which can reach 4% of global annual turnover. More importantly, the Guest WiFi portal captures verified, first-party data. Purple has collected 29 billion data points across its network (Purple internal data), demonstrating the scale of what a properly deployed guest WiFi architecture can generate.

For Retail venues, this data feeds directly into CRM systems, enabling targeted marketing campaigns based on visit frequency and dwell time. For Hospitality operators, it enables personalised re-engagement with returning guests. For Transport hubs, it provides accurate passenger flow data that informs operational decisions. For Healthcare facilities, it ensures patients and visitors receive appropriate network access while clinical systems remain completely isolated.

The Purple platform operates at 99.999% uptime (Purple internal data), ensuring that guest access is never interrupted by platform availability issues. Combined with Arista's cloud-managed infrastructure, you get an end-to-end architecture that scales from a single venue to 80,000+ locations without architectural changes.

For additional integration context, see our guide on NETGEAR Insight and Enterprise Access Points Integration with Purple WiFi . For venue operators evaluating survey tools to complement their WiFi analytics, see Design of a Survey: A Practical Guide for Venues .

Key Definitions

Arista CV-CUE

CloudVision Cognitive Unified Edge. The centralized cloud management platform used to configure, monitor, and manage Arista Wi-Fi access points, switches, and network profiles including RADIUS and SSID settings.

IT teams use CV-CUE to define SSIDs, configure RADIUS servers, set Walled Garden rules, and manage WIPS policies across all Arista APs from a single interface.

Captive portal

A web page that intercepts unauthenticated network traffic, requiring the user to interact (login, accept terms, or pay) before granting internet access. Implemented at the wireless controller or gateway level.

The primary interface for capturing first-party data and enforcing GDPR consent on Guest WiFi networks. In Arista deployments, the captive portal function is delegated to Purple as a third-party hosted service.

Walled Garden

A restricted network environment that allows access only to a specific whitelist of domains or IP addresses prior to authentication. Implemented as an ACL on the wireless controller.

Essential for allowing devices to reach the Purple splash page and Identity Providers before they have full internet access. Must be maintained as a recurring operational task as CDN IP ranges change.

PPSK (Private Pre-Shared Key)

A security mechanism that allows multiple unique passphrases to be used on a single SSID, with each passphrase mapped to a different network policy or VLAN via RADIUS authentication.

Used in multi-tenant environments to provide secure, isolated networks without broadcasting numerous SSIDs. Arista PPSK with Purple RADIUS enables dynamic VLAN steering per passphrase.

Dynamic VLAN steering

The process of assigning a client device to a specific VLAN based on RADIUS attributes (Tunnel-Type, Tunnel-Medium-Type, Tunnel-Private-Group-ID) returned during authentication, rather than a static SSID-to-VLAN mapping.

Crucial for Multi-Tenant WiFi, allowing a single SSID to serve multiple isolated user groups. Requires the switch ports connected to APs to trunk all possible tenant VLANs.

RADIUS CoA (Change of Authorization)

An extension to the RADIUS protocol (RFC 3576) that allows a RADIUS server to dynamically modify the authorization attributes of an active session without requiring re-authentication.

Used by Purple to instruct the Arista AP to grant full internet access immediately after the user completes the portal login, without requiring the device to re-associate with the SSID.

IEEE 802.1X

An IEEE standard for port-based network access control that provides an authentication mechanism for devices connecting to a LAN or WLAN. Uses EAP (Extensible Authentication Protocol) to pass credentials between the client, authenticator, and authentication server.

The correct authentication standard for Staff WiFi. Eliminates shared passphrases and enables per-user credential management integrated with corporate identity providers like Microsoft Entra ID or Okta.

MAC address randomization

A privacy feature in modern operating systems (iOS 14+, Android 10+) where the device generates a random MAC address for each Wi-Fi network it connects to, rather than using the hardware-burned MAC address.

Impacts the ability to track returning guests based solely on hardware identifiers. Requires a shift to identity-based authentication (email, social login) for accurate visitor analytics and CRM integration.

Client Isolation

A wireless network setting that prevents client devices connected to the same AP from communicating directly with each other at Layer 2, forcing all traffic through the gateway.

A mandatory security configuration for Guest WiFi to prevent lateral movement and device-to-device attacks. Also required for PCI DSS compliance when guest networks share physical infrastructure with payment systems.

EAP-TLS (Extensible Authentication Protocol - Transport Layer Security)

A certificate-based EAP method where both the client and the authentication server present X.509 certificates for mutual authentication. Considered the most secure EAP method for enterprise WiFi.

The recommended authentication method for Staff WiFi in high-security environments. Eliminates password-based credential theft by requiring a valid client certificate issued by a trusted certificate authority.

Worked Examples

A 40-site retail chain needs to deploy Guest WiFi across all locations using Arista APs. They require guests to authenticate via Google Workspace or Facebook, and need to ensure the corporate network remains completely isolated from guest traffic. They also need GDPR-compliant consent capture.

The network architect creates a dedicated Guest VLAN (VLAN 50) on the core switches and trunks it to the Arista APs. In CV-CUE, a new Guest SSID is created, mapped to VLAN 50, with Client Isolation enabled. The Captive Portal is set to Third-Party Hosted, pointing to Purple. The Walled Garden is configured to include Purple's domains, plus accounts.google.com, facebook.com, and their associated CDNs. Purple RADIUS servers are configured for authentication on ports 1812 and 1813. The Purple portal is configured with an unchecked GDPR consent checkbox and plain-language terms. When a shopper connects, they are isolated on VLAN 50, authenticate via the Purple portal using Google or Facebook, and are granted access via RADIUS CoA. Consent is logged with a timestamp and terms version in Purple, satisfying GDPR Article 7 requirements.

Examiner's Commentary: This approach ensures absolute Layer 2 isolation between corporate and guest traffic. By relying on Purple for the identity and consent layer and Arista for the enforcement layer, the retailer achieves compliance and security without complex on-premise infrastructure. The key decision here is using VLAN segmentation at the switch level rather than relying solely on the AP firewall, which provides defense in depth.

A coworking space requires Multi-Tenant WiFi for 40 member companies. They want a single SSID broadcasted, but need each member company to be isolated on their own VLAN for security. When a member's contract ends, access must be revoked immediately.

The IT manager deploys Arista APs and configures a single SSID using Arista PPSK. The SSID is configured to authenticate against Purple RADIUS. In the Purple portal, each member company is assigned a unique passphrase and a specific VLAN ID (VLAN 100 through VLAN 4000). When a user from Company A connects using their passphrase, the Arista AP queries Purple RADIUS. Purple returns an Access-Accept containing Tunnel-Type (13), Tunnel-Medium-Type (6), and Tunnel-Private-Group-ID (100). The AP dynamically steers the user to VLAN 100. When a member's contract ends, the operator revokes the passphrase in the Purple portal. The next connection attempt by any device using that passphrase receives a RADIUS Access-Reject, terminating access immediately.

Examiner's Commentary: This is the optimal architecture for multi-tenant environments. It reduces SSID overhead from 40 SSIDs to one per site, directly improving airtime efficiency and client roaming performance. The centralized revocation through Purple RADIUS eliminates the need to modify any Arista configuration when a tenant leaves, reducing operational overhead significantly.

A conference centre hosts 10 events per week, each with a different organiser who needs their own branded splash page and isolated guest network. The IT team cannot reconfigure the Arista infrastructure for each event.

The conference centre deploys a permanent Multi-Tenant WiFi architecture using Arista PPSK. Each event organiser is pre-provisioned in the Purple portal with a unique PPSK passphrase, a dedicated VLAN (e.g., VLAN 200 for Event A, VLAN 201 for Event B), and a branded splash page template. The Arista APs broadcast a single SSID year-round. The event organiser distributes their PPSK to attendees. Attendees connect, authenticate against Purple RADIUS, receive their VLAN assignment, and see the organiser's branded portal. The IT team enables and disables event passphrases in the Purple portal on a schedule, with no changes required to the Arista CV-CUE configuration.

Examiner's Commentary: This architecture separates the operational concerns cleanly: Arista handles the RF and enforcement layer, Purple handles the identity and policy layer. The conference centre IT team manages one stable infrastructure configuration. Event-specific customisation is entirely handled through the Purple portal, which can be delegated to event organisers or venue operations staff without requiring network engineering skills.

Practice Questions

Q1. A hotel guest connects to the Guest WiFi SSID, but the portal login page displays a blank screen or a timeout error on their iPhone. The corporate WiFi works perfectly. The Arista AP is online and the Purple RADIUS servers are reachable. What is the first configuration element you should verify in Arista CV-CUE, and what specific entries are you looking for?

Hint: Consider what network access the device has before authentication completes, and what the device needs to load the portal page.

View model answer

Verify the Walled Garden configuration under the Captive Portal settings in CV-CUE. The Walled Garden must explicitly whitelist the Purple portal domains: region1.purpleportal.net, venuewifi.com, and cloudfront.net. If these are missing, the device cannot load the portal assets. Additionally, check that the captive portal detection endpoints (captive.apple.com for iOS) are not being blocked. A blank screen typically indicates the portal HTML is loading but the JavaScript or CSS assets from a CDN are being blocked.

Q2. You are deploying Multi-Tenant WiFi using Arista PPSK for a coworking space with 30 member companies. Users report they can connect to the SSID and receive an IP address, but they are all landing on the default management VLAN (VLAN 1) rather than their assigned tenant VLANs. What RADIUS attributes are likely missing or misconfigured, and how do you verify this?

Hint: Think about how RADIUS instructs the AP to assign a specific network segment, and what three attributes work together to achieve this.

View model answer

The Purple RADIUS server is likely failing to return the dynamic VLAN attributes in the Access-Accept message. Three attributes must be present: Tunnel-Type (value 13, meaning VLAN), Tunnel-Medium-Type (value 6, meaning 802), and Tunnel-Private-Group-ID (the specific VLAN ID as a string, e.g., '100'). To verify, use the Arista CV-CUE troubleshooting tools to capture the RADIUS exchange for a test connection. Check the Access-Accept packet for these three attributes. Also verify that the switch port connecting the Arista AP is configured to trunk all required tenant VLANs - if the VLAN is not trunked, the AP cannot place the client on it even if the RADIUS attribute is correct.

Q3. A retail venue with 200 daily visitors notices that Purple Analytics shows a high number of very short sessions (under 1 minute), and the DHCP scope on the Guest VLAN is constantly exhausted by mid-morning, preventing new shoppers from connecting. The DHCP scope is a /24 (254 usable addresses). What are the two most likely causes, and what specific configuration changes do you make in Arista CV-CUE and the DHCP server?

Hint: Consider how the network determines when a device has left the venue, and how modern devices behave when scanning for networks.

View model answer

The two most likely causes are: first, an idle timeout that is too long, keeping sessions active for devices that have left the store; and second, MAC address randomization causing devices to appear as new clients on each visit, consuming additional IP leases. To address the idle timeout, reduce it to 10 minutes in the CV-CUE SSID session settings. This ensures stale sessions are cleared and IPs are returned to the pool. To address pool exhaustion, increase the DHCP scope to a /22 (1022 usable addresses) to accommodate the volume of unique MAC addresses generated by randomization. Additionally, reduce the DHCP lease time to 30 minutes to accelerate IP reclamation from disconnected devices.