Always-Online Connectivity Configuration Guide¶

1. Document Information¶

Product model: InHand IR302 Industrial Cellular Router
Feature: Link Backup (WAN / Cellular / Wi-Fi automatic failover)
Reference case: Ethernet WAN as Main Link, 4G cellular as Backup Link, ICMP probe to 8.8.8.8, Hot failover mode

Overall flow: Bring up at least two uplinks on the IR302 (WAN + Cellular, or WAN + Wi-Fi, or Cellular + Wi-Fi). Then enable Link Backup, pick a Main Link and a Backup Link, set an ICMP detection target, and choose a Backup mode (Hot failover / Cold failover / Load Balance). The router automatically monitors and switches the default route based on the probe result.

2. Prerequisites¶

IR302 powered on (DC 9–36 V) and reachable on its LAN port.
A laptop connected to IR302 LAN2 and configured to the same subnet (default LAN 192.168.2.0/24).
SIM card inserted (insert with the device powered OFF) if cellular is used as one of the links.
Ethernet uplink plugged into the WAN/LAN port (set as WAN) if Ethernet is used as one of the links.
Upstream Wi-Fi credentials (SSID + password) if Wi-Fi STA is used as one of the links.
A web browser for the IR302 Web UI.

Default credentials (factory):

Item	Value
LAN IP	`192.168.2.1`
Subnet mask	`255.255.255.0`
Web username	`adm`
Web password	`123456` (or random — see device label)

Change all default passwords after first login.

3. Part 1 — Log in to the IR302 Web UI¶

Connect the PC to the IR302 LAN2 port with an Ethernet cable.
Set the PC IP to the same subnet as 192.168.2.1 (e.g. 192.168.2.100/24).
Open a browser and go to http://192.168.2.1.
Log in with the default credentials (adm / 123456) or the random password on the device label.

4. Part 2 — Bring up the Uplinks¶

Before enabling Link Backup, both uplinks must already be configured and confirmed online individually. Go to Status → Network Connections and verify that each of the links you intend to use shows an active state.

4.1 Ethernet WAN¶

Go to Network → WAN/LAN Switch).
Set the WAN/LAN port to WAN mode.
Choose DHCP, Static, or PPPoE according to what the ISP provides; apply.
Plug the ISP cable into the WAN/LAN port.
Confirm on Status → Network Connections that the WAN link has obtained an IP and is online.

4.2 4G Cellular¶

Power the device OFF, insert the SIM card, power back ON.
Go to Network → Cellular.
For public IoT SIMs, no APN is required. For private / customized SIMs, fill in the APN, username, and password provided by the carrier.
Apply and wait for the cellular link to come up.
Check the Signal indicator on the front panel: red = poor (0–10), yellow = medium (11–20), green = good (21–30). Aim for green.
Confirm on Status → Network Connections that cellular has obtained an IP.

4.3 Wi-Fi STA (optional)¶

If Wi-Fi is to be used as one of the links, the IR302 Wi-Fi must be set to STA (client) mode, not AP.

Go to Network -> Switch WLAN Mode, swith from AP -> STA, apply and reboot the device.
Enable WAN(STA) mode,choose DHCP, Static, or PPPoE according to what the ISP provides; apply.
Go to Network -> WLAN Client, scan for the upstream SSID, enter the Wi-Fi password, apply.
Confirm on Status → Network Connections that Wi-Fi STA has obtained an IP from the upstream Wi-Fi.

5. Part 3 — Enable Link Backup¶

Go to Network → Link Backup.
Tick Enable.
Select Main Link and Backup Link
Click Apply.

5.1. Configure Main Link, Backup Link & Detection¶

Still on the Network → Link Backup page, fill in the parameters below.

Field	Value (this case)	Notes
Main Link	`WAN`	The preferred uplink under normal operation
Backup Link	`Cellular`	Takes over when the main link fails
ICMP detection server	`8.8.8.8`	Any always-on public IP; can be replaced with the customer's own HQ/server
Backup mode	`Hot failover`	See section 6.1 below

Click Apply to save.

5.2 Choosing the Backup mode¶

The IR302 supports three backup modes:

Mode	Behavior	When to use
Hot failover	The router keeps both links connected at all times. If the main link fails, traffic switches to the already-online backup link immediately. Uses a small amount of data on the backup link to keep it alive.	Sites where the fastest failover is critical (payments, alarms, medical, mission-critical control).
Cold failover	Only the main link is up. The backup link only dials up when the main link is down. Zero cellular usage while the main link is healthy. Failover takes a few extra seconds because the backup needs to dial up.	Sites where minimizing SIM data charges is more important than the last few seconds of failover time.
Load Balance	The router uses both links at the same time and distributes outbound traffic across them.	Throughput aggregation, dual-SIM bonded use cases.

For most fixed sites with wired WAN + 4G backup, Hot failover is the recommended default.

7. Part 5 — Verify the Default Route¶

Go to Status → Route Table.
The default route (0.0.0.0/0) should point to the Main Link interface (in this case, the WAN interface).

8. Part 6 — Test Failover¶

Test the failover by simulating a main-link outage:

Disconnect the Ethernet cable from the WAN/LAN port (or pull the upstream ISP cable).
Wait a few seconds for the ICMP probes to declare the WAN link down.
Go to Status → Route Table.
The default route should now point to the Backup Link (cellular). All outbound traffic from the LAN device is now going through 4G.

8.1 Test fallback¶

Reconnect the Ethernet cable to the WAN/LAN port.
Wait for the WAN to come back online and pass the ICMP probe.
Go to Status → Route Table again.
The default route should automatically switch back to the Main Link (WAN). No manual action required.

9. Optional — Hardening & Operations¶

9.1 Change the default Web password¶

Go to System → Admin Access (or System Settings → Management).
Enter the username, old password, and a new strong password.
Apply and save.

9.2 Restrict / open remote management¶

Go to System → Admin Access.
In the Management section, choose the service type (HTTPS / SSH), the port, and whether to allow Remote (WAN) management.
Apply and save.

9.3 Enable Device Manager (cloud O&M)¶

Go to Services → Device Remote Management Platform.
Tick Enable.
Service type: Device Manager.
Server: choose China or International based on your project region.
Account: your registered InHand Device Manager account.
Apply and save.

9.4 Backup the configuration¶

Go to System → Configuration Management.
In Router Configuration, click Backup to download a backup file.
To restore, click Import Config and reboot to apply.

10. Troubleshooting¶

Symptom	Check
Cannot open the Web UI	Same subnet as `192.168.2.1`? IP conflict? Cable OK? Try a factory reset.
Cellular cannot dial up	SIM seated? APN correct (for private SIMs)? Signal value ≥ 21?
WAN does not come up	Cable in the `WAN/LAN` port? Port set to WAN mode? Correct IP mode (DHCP / Static / PPPoE)?
Wi-Fi STA does not connect	Wi-Fi set to STA (not AP) mode? Correct SSID / password? Signal strong enough?
Failover does not happen	Is Link Backup → Enable ticked and applied? Is the ICMP target reachable from a known-good link? Is the SIM whitelisted to reach `8.8.8.8`?
Fallback to main does not happen	Is the main link actually passing the ICMP probe? Try pinging the target from the WAN side.
Both links online but traffic stuck on backup	Check Status → Route Table — the default route should match the active link. Re-apply Link Backup config.
Signal OK but cannot reach the server	LAN device gateway / DNS set correctly? SIM whitelist allows the server endpoint?

11. Safety Notes¶

Ground the device properly on industrial / outdoor / vehicle sites.
Do not hot-plug serial cables while powered.
Back up the configuration after every change.
Change default passwords periodically.
Only authorized personnel should operate the gateway.