The Connectivity Check tests what a sensor can and can't reach on a single device, without waiting for a scheduled scan. Use it when a device isn't scanning as expected and you need to know which protocols and ports the sensor can actually reach.
The Connectivity Check is a troubleshooting tool. It doesn't create or update assets, and nothing it finds is added to your discovery results. To scan a device into your inventory, use Discover now instead.
The Connectivity Check is the Lansweeper Classic DeviceTester, rebuilt in the Network Discovery hub. It has the same purpose, checks, and manual credential entry.
The check runs on the sensor
The connectivity check runs on the sensor you select, not on the hub. The result reflects that sensor's position in the network.
This matters when you have sensors in different subnets. A target that one sensor can't reach might be fully reachable from another. Run the check from the sensor that's supposed to scan the device.
The Connectivity Check uses the credentials you type on this page, not your saved discovery credentials. Enter the credentials for the protocols you want to test.
Run a connectivity check
- In the Network Discovery hub, go to Discovery results > Connectivity Check.
- Under Select IT sensor(s), select one or more sensors to run the check from.
- Enter the Target: one IP address, hostname, or FQDN. When you enter a hostname or FQDN, the sensor resolves it to an IP address before scanning.
- Set the options for the check. See Connectivity check options.
- Select Scan device.
Results stream in per check type as the sensor works through them.
Connectivity check options
| Option | Default | Description |
|---|---|---|
| Timeout | 3 seconds | Time the sensor waits for each check before moving on. |
| Ping before scanning | On | Pings the target before the other checks run. Turn this off on networks that block ICMP, so the remaining checks still run. |
| SSH Username | Not set | Username for the SSH check. |
| SSH Password | Not set | Password for the SSH check. |
| SSH Port | 22 | Port for the SSH check. |
| SIP Port | 5060 | Port for the SIP check. |
SNMP configuration
Expand the SNMP Configuration section to set SNMP credentials:
- Version: v1/v2c, v1, v2c, or v3.
- Community string for v1 and v2c.
- v3 credentials: username, auth protocol (None, MD5, or SHA), privacy protocol (None, DES, AES128, AES192, or AES256), the matching passwords, and context name.
- Custom OIDs to query.
- Skip SysOID check toggle.
Checks performed
The Connectivity Check runs these checks:
- Ping (optional)
- DNS reverse lookup
- MAC address via ARP
- TCP port scan of roughly 47 known ports
- HTTP and HTTPS
- mDNS-SD
- NetBIOS and SMB
- SNMP v1/v2c/v3
- SIP
- UPnP/SSDP
- SSH
- vPro/AMT
SMTP is not included.
Skipped checks
Some checks only run when the relevant port is open. When the port is closed, the check is reported as skipped, with the reason. A skipped check didn't apply to this device. It doesn't mean the check failed.
- HTTP and HTTPS are skipped when both port 80 and port 443 are closed.
- NetBIOS and SMB are skipped when both port 139 and port 445 are closed.
- SIP is skipped when the SIP port is closed.
- SSH is skipped when port 22 is closed.
Read and save the results
Results appear under Scan Results, grouped into categories: Layer 2, Layer 3, Application, and Authentication. Each check shows a status icon:
- A green check means the check succeeded.
- A red cross means the check failed.
- An orange triangle means the check ran but returned no data.
- A grey minus means the check was skipped. See Skipped checks.
Expand a check to see its detailed data. When you select multiple sensors, the results are grouped per sensor.
The Connectivity Check doesn't store results. If you navigate away or refresh the page, the results are lost. Save or copy them before you leave.
Two buttons let you keep the output:
- Save log downloads the results as a
.txtfile. - Copy copies the same text to your clipboard.
Both give Support the output they need, so include one when you open or update a ticket.
Related articles
- Gather logs for support. Collect the hub and sensor logs and send them to Support.
- Enable detailed logging. Raise logging verbosity to capture more detail before you reproduce an issue.
- Default installation and log file locations for Network Discovery. Find the hub and sensor install paths and log file locations.