Connected to AP but no internet connection

[ralph_uy]

Hope someone can help me out with this issue. client are connected to the AP but no internet connection Icon on mobile showing with exclamation mark

Icon on computer showing yellow triangle

Issue is, it is connected for some time then suddenly lose internet connection and then after some time will be gain internet access again. or if you disconnect and connect again you will gain internet access again.

there is a DNS server installed on one of the site DC. main DC is in another country.

DNS setup is

DNS1: ISP DNS

DNS2: DNS server IP

i will be attaching full configuration.

Setup

AP1:

Radio 2.4: channel 1,11

Radio 5.0: channel 36

Frequency Hand off: disable

AP Hand off: disable

Darrp: disable

SSID: wifi1,guest1

AP2:

Radio 2.4: channel 6

Radio 5.0: channel 40,48

Frequency Hand off: disable

AP Hand off: disable

Darrp: disable

SSID: wifi2,guest2

AP3:

Radio 2.4: channel 1,11

Radio 5.0: channel 44

Frequency Hand off: disable

AP Hand off: disable

Darrp: disable

SSID: wifi1,guest1

[ralph_uy]

i tried which mode in 5.0 is causing the issue, found out it is 802.11ac and 802.11a

so temp i configure it to be 802.11n.

[Fortichef]

Hi Ralph, did you find anything? I'm with fortinet support on this problem aswell and they're offering me an update on the fortiaps as a next step... They've put 2.4 on n and 5ghz on ac as previous step. But we just lost connection again. However I'm in doubt if would just change the fortiap-u for regular fortiaps. Since I haven't experienced this with regular fortiaps.

[ralph_uy]

i give up on troubleshoot this FortiAP-U, i just keep 5.0Ghz signal to 802.11n

i tried all possibility of setup. they even replace my AP's with a new one but still the same problem.

i will probably resume troubleshooting one i have tiem again. but for now i will keep it as it is.

[Ahslan]

Sad to hear others still having this issue as well. I experienced by and large the same issue you described 3 years ago when using 320C's. Ended simply giving up on them and moving back to Aruba APs. While not nearly as easy to manage, the Aruba APs have been rock solid and have never had such issue

[ralph_uy]

i have to agree. the vendor deployed the aruba entry level AP, as small as mouse temporary while waiting for the replacement of FortiAP. and it is doing the job well done for a month without any issue.

this fortiAP is pretty expensive to be failing like this.

[Epitaph91]

I am having the same issues now... I will get clients that randomly get connected and are unable to access internet or if its a bridge no access to local resources.

I have about 35 WAPs that range from 221E's to 421E's and Fortinet had me dowgrade the code on my 421E's to support my firewall code 6.0.2 which made no difference.

[sanderl]

Hello, here exactly the same situation 60E fortiwifi, 3x 221C all latest fw... frequent wifi issues. Exclamation mark etc. Cabled works fine though. I have tried literally everything but just does not work. Currently rebooting APs and FW daily...

[smartfoneaddict]

Same issue with FortiWifi 40C and FP223 access point (all on latest firmware).  Recently various devices connected to the AP will indicate that they do not have access to the Internet while remaining connected to the AP and all lights on the AP continuing to show green.  Can find nothing in the logs.  Disconnecting from the AP and reconnecting seems to fix it.  But the fact that the disconnect happens nearly simultaneously on various devices and only appears to be resolved by disconnecting and reconnecting, makes it hard to believe that it is a client device side issue.  (Still trouble shooting).

[trinehart150]

Is there any official fix for this? We are currently using U-421EV APs. The exact same thing is happening to in my environment. Clients are staying connected to SSID, but lose internet connectivity. They are not able to ping gateway, but hold onto the band and channel in NIC info. Only way for them to fix is to manually disconnect and then reconnect to the APs. We have other APs in our environment that are not experiencing this issue. Going to 802.11n is not a viable option. This issue happened on the 5.4.6 Firmware, as well as the recent 6.0.1 Firmware as well.

[deanshomer]

Having the same issues with clients disconnecting randomly. We have to reboot the APs every few hours to force client resets which is obviously less than ideal. Using FortiAP 221E in tunnel mode to Fortigate wifi controller. I have a support case opened with no resolution but will post back if anything comes from it.

Update: Found out that the CAPWAP packets were getting fragmented due to the tunneling over and IPSEC connection back to the controller. The solution for this particular problem is to adjust the tunnel MTU on the AP profile in order to avoid CAPWAP fragmentation.