WiFi not connecting under Ubuntu Server - Lenovo Thinkpad T430

Support and Help
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1

Ubuntu Version:

  • ubuntu-24.04.3-live-server-amd64.iso
  • ubuntu-25.10-desktop-amd64
  • ubuntu-25.10-live-server-amd64

Desktop Environment (if applicable): N/A

Problem Description:
When trying to install Ubuntu Server on my Lenovo Thinkpad T430 the WiFi will not connect.

I have been running Ubuntu Desktop (Ubuntu 24.04.3 LTS and earlier versions) on the same machine for many years with no WiFi connection issues. I want to use the machine not as a playground to explore having a Server, failing at step 1 :roll_eyes:

If I start the 25.10 desktop live is from USB I can also connect to my WiFi without problems.

I did go through with an install of 25.10 server, with the hope to then manually connect to WiFi but I was not able to. This exceeds my skills.

I did check /etc/netplan/00-installer-config.yaml the wifi information in there is correct.

The best clue that I might have is the kern.log ending with many repeats of wlp3s0 authentication issues.

Any pointers are welcome and I can share outputs etc.

Relevant System Information:
WiFi chipset information:

03:00.0 Network controller [0280]: Intel Corporation Centrino Advanced-N 6205 [Taylor Peak] [8086:0085] (rev 34)

Screenshots or Error Messages:
installer kern.log

2026-01-15T10:57:50.049339+00:00 ubuntu-server kernel: iwlwifi 0000:03:00.0: Radio type=0x1-0x2-0x0
2026-01-15T10:57:50.351403+00:00 ubuntu-server kernel: iwlwifi 0000:03:00.0: Radio type=0x1-0x2-0x0
2026-01-15T10:57:57.923350+00:00 ubuntu-server kernel: wlp3s0: authenticate with 88:0f:a2:bd:4d:26 (local address=60:67:20:03:90:fa)
2026-01-15T10:57:57.923379+00:00 ubuntu-server kernel: wlp3s0: send auth to 88:0f:a2:bd:4d:26 (try 1/3)
2026-01-15T10:57:57.973396+00:00 ubuntu-server kernel: wlp3s0: authenticate with 88:0f:a2:bd:4d:26 (local address=60:67:20:03:90:fa)
2026-01-15T10:57:57.973412+00:00 ubuntu-server kernel: wlp3s0: send auth to 88:0f:a2:bd:4d:26 (try 1/3)
2026-01-15T10:57:57.993406+00:00 ubuntu-server kernel: wlp3s0: authenticated
2026-01-15T10:57:57.995376+00:00 ubuntu-server kernel: wlp3s0: associate with 88:0f:a2:bd:4d:26 (try 1/3)
2026-01-15T10:57:58.004410+00:00 ubuntu-server kernel: wlp3s0: RX AssocResp from 88:0f:a2:bd:4d:26 (capab=0x1431 status=0 aid=6)
2026-01-15T10:57:58.025437+00:00 ubuntu-server kernel: wlp3s0: associated
2026-01-15T10:57:58.182341+00:00 ubuntu-server kernel: wlp3s0: deauthenticating from 88:0f:a2:bd:4d:26 by local choice (Reason: 1=UNSPECIFIED)
2026-01-15T10:58:01.429388+00:00 ubuntu-server kernel: wlp3s0: authenticate with 88:0f:a2:bd:4d:26 (local address=60:67:20:03:90:fa)
2026-01-15T10:58:01.429409+00:00 ubuntu-server kernel: wlp3s0: send auth to 88:0f:a2:bd:4d:26 (try 1/3)
2026-01-15T10:58:01.436338+00:00 ubuntu-server kernel: wlp3s0: authenticated
2026-01-15T10:58:01.437388+00:00 ubuntu-server kernel: wlp3s0: associate with 88:0f:a2:bd:4d:26 (try 1/3)
2026-01-15T10:58:01.449374+00:00 ubuntu-server kernel: wlp3s0: RX AssocResp from 88:0f:a2:bd:4d:26 (capab=0x1431 status=0 aid=6)
2026-01-15T10:58:01.478404+00:00 ubuntu-server kernel: wlp3s0: associated
2026-01-15T10:58:01.514367+00:00 ubuntu-server kernel: wlp3s0: deauthenticating from 88:0f:a2:bd:4d:26 by local choice (Reason: 1=UNSPECIFIED)
2026-01-15T10:58:04.769349+00:00 ubuntu-server kernel: wlp3s0: authenticate with 88:0f:a2:bd:4d:26 (local address=60:67:20:03:90:fa)
2026-01-15T10:58:04.769368+00:00 ubuntu-server kernel: wlp3s0: send auth to 88:0f:a2:bd:4d:26 (try 1/3)
2026-01-15T10:58:04.775368+00:00 ubuntu-server kernel: wlp3s0: authenticated
2026-01-15T10:58:04.775382+00:00 ubuntu-server kernel: wlp3s0: associate with 88:0f:a2:bd:4d:26 (try 1/3)
2026-01-15T10:58:04.786350+00:00 ubuntu-server kernel: wlp3s0: RX AssocResp from 88:0f:a2:bd:4d:26 (capab=0x1431 status=0 aid=6)
2026-01-15T10:58:04.804428+00:00 ubuntu-server kernel: wlp3s0: associated
2026-01-15T10:58:04.909360+00:00 ubuntu-server kernel: wlp3s0: deauthenticating from 88:0f:a2:bd:4d:26 by local choice (Reason: 1=UNSPECIFIED)
2026-01-15T10:58:08.157360+00:00 ubuntu-server kernel: wlp3s0: authenticate with 88:0f:a2:bd:4d:26 (local address=60:67:20:03:90:fa)
2026-01-15T10:58:08.157386+00:00 ubuntu-server kernel: wlp3s0: send auth to 88:0f:a2:bd:4d:26 (try 1/3)
2026-01-15T10:58:08.166408+00:00 ubuntu-server kernel: wlp3s0: authenticated
2026-01-15T10:58:08.166424+00:00 ubuntu-server kernel: wlp3s0: associate with 88:0f:a2:bd:4d:26 (try 1/3)
2026-01-15T10:58:08.181354+00:00 ubuntu-server kernel: wlp3s0: RX AssocResp from 88:0f:a2:bd:4d:26 (capab=0x1431 status=0 aid=6)
2026-01-15T10:58:08.205369+00:00 ubuntu-server kernel: wlp3s0: associated
2026-01-15T10:58:08.314340+00:00 ubuntu-server kernel: wlp3s0: deauthenticating from 88:0f:a2:bd:4d:26 by local choice (Reason: 1=UNSPECIFIED)

dmesg showing wifi relevant lines:

[ 16.221051] kernel: iwlwifi 0000:03:00.0: loaded firmware version 18.168.6.1 6000g2a-6.ucode op_mode iwldvm
[ 16.275812] kernel: mc: Linux media interface: v0.10
[ 16.332022] kernel: Bluetooth: hci0: BCM: chip id 63
[ 16.332087] kernel: Bluetooth: hci0: BCM: features 0x07
[ 16.349029] kernel: Bluetooth: hci0: BCM20702A
[ 16.349140] kernel: Bluetooth: hci0: BCM20702A1 (001.002.014) build 0000
[ 16.403028] kernel: videodev: Linux video capture interface: v2.00
[ 16.506691] kernel: Bluetooth: hci0: BCM: firmware Patch file not found, tried:
[ 16.506782] kernel: Bluetooth: hci0: BCM: ‘brcm/BCM20702A1-0a5c-21e6.hcd’
[ 16.506898] kernel: Bluetooth: hci0: BCM: ‘brcm/BCM-0a5c-21e6.hcd’
[ 16.724018] kernel: usb 1-1.6: Found UVC 1.00 device Integrated Camera (5986:02d5)
[ 16.736099] kernel: usbcore: registered new interface driver uvcvideo
[ 16.836022] kernel: iwlwifi 0000:03:00.0: CONFIG_IWLWIFI_DEBUG disabled
[ 16.836376] kernel: iwlwifi 0000:03:00.0: CONFIG_IWLWIFI_DEBUGFS enabled
[ 16.836607] kernel: iwlwifi 0000:03:00.0: CONFIG_IWLWIFI_DEVICE_TRACING enabled
[ 16.836836] kernel: iwlwifi 0000:03:00.0: Detected Intel(R) Centrino(R) Advanced-N 6205 AGN, REV=0xB0
[ 16.876024] kernel: ieee80211 phy0: Selected rate control algorithm ‘iwl-agn-rs’
[ 16.881018] kernel: iwlwifi 0000:03:00.0 wlp3s0: renamed from wlan0

What I’ve Tried:
I tried to use the current and current LTS server iso to install. During the installer run I tried to connect to the WiFi which always got stuck at acquiring DNS.

2

Have you tried rebooting the router?

3

Also try

echo “options iwlwifi swcrypto=1” | sudo tee /etc/modprobe.d/iwlwififix.conf > /dev/null

Reboot to test. If it doesn’t help then run:

sudo rm /etc/modprobe.d/iwlwififix.conf

Then re-reboot

4

Hey, thanks for this I will try.

Since writing the post I have also tried a number of things.

I did go through my netplan yaml file based on these examples.

I learned that I can connect to my mobile hotspot with no password set no problem.

I can’t connect when using WPA2-personal, WPA2-3 or WPA3-personal security settings.

5

this did nothing.

although I saw that

deauthenticating from 88:0f:a2:bd:4d:26 by local choice (Reason: 1=UNSPECIFIED)

changed to

deauthenticating from 88:0f:a2:bd:4d:26 by local choice (Reason: 3=DEAUTH_LEAVING)

but I only checked after rebooting the second time (no modprobe.d).

Was the intention to DELETE the modprobe.d file or just remove what I added?

I will reboot the router and try again tomorrow then.

will also try this https://askubuntu.com/questions/1180240/wifi-connection-error-deauthenticating-by-local-choice-reason-3-deauth-leavin

6

Just the file we created. The modprobe.d directory contains other files with kernel module settings

7

https://askubuntu.com/questions/1180240/wifi-connection-error-deauthenticating-by-local-choice-reason-3-deauth-leavin

Found that after searching for the message you got

8

Hi, thanks I found this one as well. When I ran

sudo modprobe -r iwlwifi

the system went into some kind of reboot. I am not sure how it is called. Looked similar to when it starts up. Is that what is supposed to happen?

A different thought was that it must be linked to any differences between how Ubuntu Desktop and Ubuntu Server connect or the security when establishing the WiFi connection. Does anyone have ideas here?