Wireless Clients Can't Access Internet – DHCP from WLC, LAN OK

[phuocntlk135]

Hi everyone,

I’ve recently deployed a wireless lab using a vWLC 9800-CL, and I need some help troubleshooting Internet access for wireless clients.

Here’s a quick summary of my setup:

• WLC 9800-CL connected via trunk port to a Cisco 3750 L3 switch.

• VLANs:

  • VLAN 10 – Management

  • VLAN 20 – SSID 1

  • VLAN 30 – SSID 2

• DHCP for clients is configured directly on the WLC.

• Trunk from the switch goes to an ASA firewall that’s connected to the Internet.

• LAN clients (wired) can access the Internet without any issue.

• Wireless clients (connected via SSID 1 or SSID 2) get the correct IP address from DHCP, but can’t access the Internet.

I’ve already:

• Verified VLAN tagging and trunk configuration on all switchports.

• Ensured ASA has NAT and routing properly configured.

• Tested connectivity from LAN clients to Internet (works fine).

 

My question: What additional steps should I check to allow wireless clients to reach the Internet? Is there a common issue with routing or NAT from WLC subnets that I might be missing?

Any advice or tips are appreciated. Thanks in advance!

[marce1000]

  - Start with a sanity check of the vWLC 9800-CL configuration using the CLI command
     show tech wireless and feed the output from that into Wireless Config Analyzer
     Use the command mentioned in green, do not use a show tech-support for the above procedure,

   For DHCP follow these guidelines with an external  DHCP service preferred :
          https://www.cisco.com/c/en/us/td/docs/wireless/controller/9800/technical-reference/c9800-best-practices.html#DHCPbridgingandDHCPrelay

   M.

[Scott Fella]

@phuocntlk135 Again, you might never get this to work with an unsupported hypervisor.  DHCP from the controller is not recommended and you should do that from a dhcp server or your L3.  DHCP from the controller will not work if you have dhcp proxy enabled and you have a firewall.  Most firewalls don't like dhcp proxy.

[Saikat Nandy]

Can I have a 'show tech wireless' from controller please