1. Purpose
To outline a systematic troubleshooting approach for situations where wireless clients cannot obtain an IP address via DHCP, despite the Pronto router, switch, and access points being operational and wired clients working normally.
2. Scope
This SOP applies to cloud-managed Pronto deployments where:
PC61 (Pronto router) acts as the gateway and DHCP server
Managed switches distribute VLAN traffic
Access Points (APs) broadcast SSIDs for wireless connectivity
These networks are deployed at cafes, restaurants, bars, and pubs supporting guest WiFi, staff devices, and POS systems.
3. Background – DHCP in Wireless Networks
When a wireless client connects to an SSID, the following sequence occurs:
Client associates with the Access Point
AP forwards traffic to the Switch
Switch sends traffic to the Router
Router’s DHCP server assigns an IP address
Typical path:
Client → Access Point → Switch → Router → DHCP Response
If DHCP traffic from wireless clients does not reach the router, clients will connect to WiFi but fail to obtain an IP address.
4. Problem Description
The following conditions are observed:
Router, switch, and APs are online in the controller
Wired devices connected to the switch are working normally
Wireless clients can see the SSID
Wireless Clients cannot obtain an IP address
Devices remain stuck at “Obtaining IP Address”
This indicates a problem in wireless VLAN configuration or DHCP forwarding for wireless traffic.
5. Business Impact
Guest WiFi unavailable
Staff mobile devices unable to access internal applications
Tablets or handheld POS devices cannot connect
Customer complaints due to WiFi failure
6. Common Causes
SSID mapped to incorrect VLAN
VLAN not created or not allowed on switch trunk port
Switch port connected to AP missing required VLANs
DHCP server disabled or scope is not defined for the VLAN
7. Troubleshooting Steps
Step 1 – Verify SSID Configuration
Log in to the cloud controller dashboard.
Navigate to Wireless → SSID configuration.
Check the VLAN ID mapped to the SSID.
Ensure the correct VLAN is assigned.
Step 2 – Verify VLAN Exists in Network Configuration
Navigate to Network → VLAN settings and verify:
Wireless VLAN exists
DHCP server is enabled for that VLAN
Subnet configuration is correct.
Step 3 – Check Router or Switch Port Connected to AP
Navigate to Network → Wired Config (Router) → Port Configuration
Navigate to Network → Switch → Port Configuration.
Locate the port where the AP is connected.
Verify that the port is configured as Trunk.
Confirm that the SSID VLAN is allowed/tagged on that trunk port.
If the VLAN is missing, wireless traffic will not reach the router.
Step 5 – Check DHCP Server Status
Navigate to Router → Network / Vlan - DHCP configuration.
Verify:
DHCP is enabled
IP pool is available
No DHCP exhaustion.
Step 6 – Test with Another Wireless Client
Connect another device to the SSID to confirm that the issue is not client-specific.
If multiple clients fail, the issue is network configuration related.
9. Resolution
Based on the findings:
If VLAN Not Allowed/tagged on Router & Switch Ports
Add the wireless VLAN to the trunk port.
If SSID Mapped Incorrectly
Update the SSID configuration with the correct VLAN.
If DHCP Disabled
Enable DHCP server for the wireless VLAN.
After applying changes:
Reconnect the wireless client
Verify IP address assignment.
10. Expected Result
Wireless clients successfully receive IP addresses via DHCP.
Devices connect to the network normally.
Internet access works for wireless users.
Network services are restored.