Client made a request to the DHCP server, but it did not respond.

[Telthanya]

Dear all Expert,

I go to menu Wireless > Access Point > Connection Log. I found a lot of notes about this topic. I think that this logs maybe root cause. Which make a lot of my customers (that using a wireless client) cannot access the WLAN and the IP address was not obtained from the DHCP server.

Diagram as below :
Wireless Client <> AP(MR52, MR53E) <> ASW(MS225) <> CSW(MS425) <> ISP CSW

Noted :
From AP to ISP CSW using Trunk VLAN 96 (DHCP Server provided from VLANIF96 on ISP CSW)

Any suggestions of where to look would be a great help, thanks in advance.

[DarrenOC]

Morning @Telthanya 

Is this a new deployment?

Are you saying that wireless clients are able to connect to the SSIDs but aren’t getting an IP by DHCP?

Have you checked the firewall setting on the SSIDs that it’s not set to Block LAN? As I assume this is where your DHCP server resides.

[Telthanya]

Hi @DarrenOC

Is this a new deployment?

# No, Its deploy long times ago. My wireless network provide in Airport. Which between COVID19 has this issue also, But not much effect due to a little bit of client. Now, we have more client. It certainly had a noticeably greater impact. So I need to urgently solve this problem.

Are you saying that wireless clients are able to connect to the SSIDs but aren’t getting an IP by DHCP?
# Yes, i mean like that.

Have you checked the firewall setting on the SSIDs that it’s not set to Block LAN?
# I'm not sure about your mention. Please told me about Menu that i can see your mention.

Thanks sir.

[DarrenOC]

Hi @Telthanya 

It’s under Wireless > Configure > Firewall and Traffic Shaping

[DarrenOC]

 they’ll be an option for Destination - Local LAN.  What is that set to?

Have you checked your DHCP scope isn’t depleted?  Is it sized appropriately for the number of devices connecting 

[Telthanya]

Dear @DarrenOC 

they’ll be an option for Destination - Local LAN.  What is that set to?
# As image sir.

Have you checked your DHCP scope isn’t depleted?

# DHCP belong ISP (DHCP Server provided from VLANIF96 on ISP CSW). I just make sure about my configure on Meraki that is correct first.

[Telthanya]

Hi @DarrenOC 

Have you any suggestion for me ?

[Telthanya]

..

[alemabrahao]

Check on both AP and switch the trunk port configuration.

[Telthanya]

Hi @alemabrahao 

Checked, Its correct and works. This issue occur some client not all.

[alemabrahao]

Do you have 802.11w enabled? 

[Telthanya]

Hi @alemabrahao 

Where is this function on Meraki dashboard ? Pls let me know ill check it.

[alemabrahao]

On your SSID configurations.

[Telthanya]

Hi @alemabrahao 

Disable. Due to My Wireless Network is Open Network. Its Public WiFi.

[alemabrahao]

Do you have enough IP in your DHCP scope?

[Telthanya]

Hi @alemabrahao 

It have enough. Have free about 30% of /19

[alemabrahao]

In this case my suggestion is to open a support case.

[RaphaelL]

What MR version are you running ?

These false reports for Client made a request to the DHCP servers were kinda fixed in MR29.X

[Telthanya]

Hi @RaphaelL 

What MR version are you running ?

# MR 28.6.1 sir.

These false reports for Client made a request to the DHCP servers were kinda fixed in MR29.X
# Really ? Can you provide reference Doc or Article about this?

[RaphaelL]

Depending on your model and features : 

MR29.1 

• AP may experience DHCP failures on 2.4 GHz WPA2 Enterprise SSIDs (MR42)

MR29.4 

• ‘No DHCP response’ error using L3 Roaming

I would suggest upgrading to the lastest stable version ( 29.5.1 ) and report your results. 

In our case it fixed the false reports. If there is really an issue with your DHCP server , then this wont fix it obviously.

[Telthanya]

Hi @RaphaelL 

My network not L3 Roaming. I using Bridge mode and i think after upgraded. The issue still exists.

 Do you have any suggestion for me ? (in addition to the above.)

[RaphaelL]

Well you will have to take a packet capture to identify if the DHCP server is really receiving the requests and responding.