Connectivity Actions

How Are Connectivity Failures Detected?

Marvis uses anomaly detection or scope analysis to detect connectivity failures, as follows:

• Anomaly Detection—Marvis detects issues when they start to occur at your site, such as multiple clients failing for the same reason. Anomalies are failures that occur across most, but not all, devices on your site. The Details page (Anomaly Detection Event Card), which you can open with the View More link, lists the component that probably caused the failure. For more information about anomaly detection, see Anomaly Detection Event Card.

  After you fix the issue, the action automatically resolves and appears in the Latest Updates section within 24 hours.

• Scope Analysis—When the failure rate across all clients at your site is 100 percent, Marvis performs a scope analysis on the issue to determine the root cause of such a failure. Marvis provides the details of the affected clients—MAC address, VLAN, and WLAN for which Marvis triggers the scope anomaly. Marvis indicates the issue that needs to be fixed, whether it is a RADIUS, Domain Name System (DNS), or Dynamic Host Configuration Protocol (DHCP) server; a WLAN; or an access point (AP). Here is an example that shows how Marvis reports an issue based on scope analysis:

  

  After you fix the issue, the action automatically resolves and appears in the Latest Updates section within an hour.

Authentication Failure

The Authentication Failure action shows both 802.1x and preshared key (PSK) failures. Click the Authentication Failures button to see the impacted devices and the recommended actions in the lower part of the page.

• 802.1x Failures
• PSK Failures

802.1x Failures

The 802.1x failures include the following:

• RADIUS Server Missing Events: These events are triggered when a RADIUS server at a site does not respond to Extensible Authentication Protocol (EAP) requests. This failure to respond results in a high number of clients failing 802.1X authentication on the wireless LAN (WLAN). Marvis might detect failures across multiple APs broadcasting to the same 802.1x WLAN. These failures indicate that a RADIUS server is either configured wrong or is missing from the network. In this case, you'll need to check if the RADIUS server is online and reachable.

• RADIUS Missing AP Events: These events are triggered when clients connecting to a few APs fail to authenticate to a WLAN that has a RADIUS server configured for EAP authentication. This RADIUS event indicates that you have not configured these APs as network access service (NAS) clients on the RADIUS server. You must add the missing APs to the RADIUS configuration to resolve the issue.

Here's an example that shows how Marvis Actions reports an 802.1x authentication failure. Note the Authentication Failure Details page showing the information:

Note:

Marvis detects authentication failures even in wired-only deployments.

DHCP Failure

The DHCP Failure action appears when Marvis detects DHCP failures due to offline or unresponsive DHCP servers (DCHP timeouts).

Marvis provides details about these DHCP servers, enabling you to troubleshoot and resolve the problem quickly. When you see a DHCP Failure action, ensure that the DHCP servers are online and can lease IP addresses.

If you see a View More link in the DHCP Failure table, click the link to open the Event Card. For more information, see Anomaly Detection Event Card.

ARP Failure

An Address Resolution Protocol (ARP) Failure action appears when an unusually large number of clients experience issues with the ARP gateway. These issues include Gateway ARP timeout and excessive ARP. When you see an ARP Failure action, you must verify that the gateway is online and reachable. You must also ensure that the network is free of congestion.

DNS Failure

Marvis Actions detect unresponsive DNS servers for your site if a large number of clients experience DNS errors when using the network. If you see this action on your dashboard, you need to check that all your DNS servers are online and reachable.