Introducing Port Advisor: Centralized Wired Network Diagnostics in Nebula Pro Pack License

Zyxel_Lynn

With the release of Nebula 19.10,Zyxel brings Port Advisor, a Pro Pack-exclusive feature, to simplify wired network troubleshooting. Designed to be the wired equivalent of Wireless Health, Port Advisor provides a single-pane-of-glass view into potential anomalies occurring across your switches.

This article will walk you through what Port Advisor does, how it works, current model support, and how you can interact with its features for real-world network insights.

What Is Port Advisor?

Port Advisor is a diagnostic dashboard within the Nebula Control Center (NCC) that provides visibility into network abnormalities on managed switches.

It monitors and reports on:

• Network loops (via Loop Guard)
• Unauthorized switch connections (via BPDU Guard)
• Faulty cabling (via CRC and link status analysis)
• Broadcast and multicast storms (via Storm Control)
• Bandwidth usage spikes (via TX/RX counters)

Think of it as "Wired Health" for your switch infrastructure.

Key Features and Benefits

Feature	Detection Method	Action
Loop Detection	Event Logs	Shut down port
BPDU Guard	Event Logs	Shut down port
Bandwidth Pulse	TX/RX Port Counters	Threshold-based alerts
Storm Events	Packet rate monitoring	Limit broadcast/multicast
Cable Health	CRC + Link status changes	Alert only

• Offers interactive graphs, percentage breakdowns, and port-specific anomaly tracking.
• Enables immediate action (e.g., shutting down ports or rate limiting traffic).
• Provides per-category suggestions for troubleshooting.

Model Support and Limitations

Full Feature Support (All categories):

• Currently only available on the XMG-2230 Series (requires latest FiOS firmware).

Partial Support (Bandwidth Pulse and Cable Help):

• Available on all Zyxel Nebula switches, including older models.

More models are expected to support full Port Advisor functionality with upcoming firmware updates (tentatively by October).

Visual Insights

The Port Advisor dashboard includes:

• Pie Charts: See the percentage of each anomaly.
• Time Graphs: Visualize when and how often issues occur.
• Category Breakdown: Expand each issue type to see affected switches and ports.
• Historical Review: Investigate trends by adjusting the time window.

Port Actions

Issue	Available Action
Loop or BPDU Events	Shut Down Port directly
Broadcast/Multicast Storms	Limit PPS Threshold
Others (e.g., Bandwidth)	No direct action but alert customization available

You can re-enable any shutdown port via the Port Advisor interface or from the Switch Port Settings page.

Anomaly Detection Engine

Port Advisor uses two data sources:

1. Event Logs (for Loop, BPDU, Storm, PoE issues)
2. Port Counters (for Bandwidth and Cable Health)

If logs are missing (e.g., due to a switch reboot), Port Advisor will have no data to process.

Cable Health: Two Detection Conditions

1. CRC-Based:
   • ≥ 50 CRC errors per polling interval
   • Supported by all switches
2. Link-Flap-Based:
   • ≥ 2 CRC errors + ≥ 15 link status changes per polling
   • Requires latest firmware (XMG-2230 only)

Alerts and Customization

Port Advisor anomalies can trigger email alerts, which include:

• Switch name
• Affected port
• Category and severity
• Whether the port is an uplink (highlighted for priority)

Bandwidth Pulse Sensitivity

Adjust the bandwidth pulse threshold from 60%to 95% of link speed under:

Organization-wide > Configure >Alert Settings > Port Advisor

By default, the threshold is 85%.

Recommended Deployment Practices

To effectively isolate storm sources:

• Set lower PPS thresholds on access switches
• Gradually increase thresholds up the topology
• Example:
  • Access Layer: 10 PPS
  • Aggregation: 100 PPS
  • Core: 500–1000 PPS

This makes it easier to pinpoint the origin of storm events using Port Advisor.

Licensing and Limitations

• Pro-Pack license required to access Port Advisor UI and alerts.
• If expired:
  • UI is hidden with a license prompt
  • Detection continues silently in background
  • Historical data is retained and viewable upon license renewal

Summary Table: Detection Methods & Firmware Requirements

Category	Detection Source	Firmware Upgrade Required
Loop/BPDU Guard	Event Logs	Yes
Bandwidth Pulse	Port Counters	No
Cable Health (CRC)	Port Counters	No
Cable Health (Link Status)	Logs + Counters	Yes (XMG-2230)
Storm Events	Logs	Yes
PoE Events	Event Logs	Yes

Port Advisor empowers network admins with proactive visibility into wired network health, bridging a long-standing gap in switch diagnostics. While full support is currently limited to the XMG-2230, even older switches benefit from critical insights like bandwidth spikes and cabling issues.