43658 - LOG_ID_EVENT_WIRELESS_STA_DHCP_NO_RESP

[F_Mehmood]

Hello,
For our customer who has a full forti-stack: Fortigate firewall, FortiSwitch and the FortiAPs, the WIFI guest users are not getting the IP addresses and the error 

DHCP-no-response

Warning

DHCP server not responding for client (Client device Mac-address)

The link to the Fortigate documentation which shows the Log ID:

https://docs.fortinet.com/document/fortigate/7.2.7/fortios-log-message-reference/43658

1:) I have a question is there a separate document that advises the steps to troubleshoot this issue related to the log messages on the firewall not only for this issue but also for the other issues?
2:) Lastly the issue started after the firmware upgrade from version 7.0.12 to 7.2.7 last week?

3:) What are the steps to troubleshoot the issue?
Many thanks

Faisal

[AEK]

Hello

First try see if your FG can see the incoming DHCP requests:

diag sniffer packet <GUEST_INTERFACE_NAME> 'port 67 or port 68' 4

On the other hand, do you have an ippool object defined in the same IP range as the guest range? If so, try disable the "ARP Reply" flag from this IP pool object.

[F_Mehmood]

Hello, AEK,
This issue is resolved now as I disabled the interface and enabled it.

However the main question relates to the Log IDs which we see in the firewall and the above link explains it as well but does not give any solution for it.
Is there a document from Fortinet that explains how to resolve those issues?

Many thanks

Faisal Mehmood

[AEK · Accepted solution]

Hi @F_Mehmood 

There is a general troubleshooting guide in cookbook.

https://docs.fortinet.com/document/fortigate/6.2.16/cookbook/244292/troubleshooting

On the other hand you can find more specific troubleshooting methods for many issues by searching in Tech Tips and Troubleshooting Tips within the knowledge base, including DHCP related issues.

https://community.fortinet.com/t5/FortiGate/tkb-p/TKB20

[F_Mehmood]

Thank you for your advise.