Troubleshooting Device Reachability in Auvik

Introduction

If Auvik cannot discover or read a device at a specific IP address, begin by verifying communication between the Auvik collector and the device. The collector must receive an ICMP Echo Reply from the target IP before Auvik can continue with discovery and device identification.

Symptoms

A device may:

• Not appear in Auvik.
• Appear offline or as a generic device.
• Show an incorrect monitored IP address.
• Fail SNMP or CLI checks because the collector cannot reach the device.

Common Causes

Device reachability issues can occur for several reasons, including:

• ICMP Echo Reply is blocked by the device, firewall, or ACL.
• The target IP is not included in a discovered subnet.
• The discovered subnet is assigned to the wrong collector.
• The device is behind NAT from the collector’s perspective.
• The Monitored IP configured in Auvik does not match the device’s current management IP address.
• Duplicate IP addresses cause inconsistent connectivity.
• The device’s management protocols are blocked or unavailable.

Resolution

Step 1: Test Connectivity from the Auvik Collector

From the Auvik collector, ping the target device IP address:

ping <device_ip>

If the collector does not receive an ICMP Echo Reply, allow ICMP Echo Reply from the collector to the device and through any intervening firewalls or ACLs.

Depending on the collector, you can log in to the collector’s shell by following the steps in the article about diagnosing discovery scanning with the Auvik collector.

Step 2: Verify the Discovered Subnet and Collector

Confirm that the target IP is within a discovered subnet:

1. Go to Discovery > Manage.
2. Confirm that the subnet containing the target IP is listed.
3. Confirm that the subnet is assigned to the correct collector.
4. Add or update the discovered subnet if necessary.

Step 3: Check for NAT

Confirm that the device is not behind NAT from the collector’s perspective.

The collector must be able to reach the device’s actual management IP. NAT or port forwarding can prevent Auvik from correctly identifying the device or associating it with the expected IP address.

Step 4: Verify the Monitored IP Address

Open the device details in Auvik and verify that the Monitored IP matches the device’s current management IP address.

If the monitored IP is incorrect, update the device configuration or resolve the underlying addressing issue before continuing.

Step 5: Verify SNMP or CLI Access

Once the collector receives an ICMP Echo Reply, Auvik can continue with SNMP or CLI checks.

Confirm that:

• The required SNMP or CLI credentials are configured in Auvik.
• The device allows the collector’s IP address.
• Required management ports are permitted through firewalls and ACLs.
• The configured credentials match the device configuration.

Step 6: Check for Duplicate IP Addresses

Duplicate IP addresses can cause devices to appear intermittently online or offline.

Review the following on the network infrastructure:

• ARP tables.
• MAC address tables.
• DHCP lease information, if applicable.

Resolve any IP conflicts before rescanning the device in Auvik.

Additional Considerations

If the device responds to pings from another workstation but not from the Auvik collector, compare the network path between each source and the device. Differences in VLANs, routing, firewall policies, NAT, or security controls may prevent the collector from reaching the management interface.

Summary

When Auvik cannot discover or read a device at a specific IP address:

1. Confirm the collector receives an ICMP Echo Reply.
2. Verify the IP is within a discovered subnet assigned to the correct collector.
3. Confirm the device is not behind unsupported NAT or port forwarding.
4. Verify that the Monitored IP matches the device’s current management IP.
5. After reachability is restored, verify SNMP or CLI credentials and rescan the device.

Network routing, NAT, firewall rules, ACLs, and device management settings may require assistance from a network administrator.