Repairing beeping Lenovo T440p

Laptop powers on but nothing on screen. This is often because eeprom (Winbond W25Q32FVSIQ, 32Mbit / 4MB, 2.7V - 3.6V, SPI/QPI) loses programming over time and one day laptop will simply no longer boot. At first it will blink some leds on keyboard and turns off. Then it will degrade to just beeping on boot. Get CH341A programmer. Since flash is 3.3V model do not use included 1.8V adapter. Make sure you use 3.3V, not 5V - there's jumper on CH341A. Download drivers, tools and bios images from . See for how to connect wires and use programming tool. Remove battery and open bottom of laptop, remove RAM and connect programmer to flash chip on U49. Connect programmer to USB port on Windows PC, install drivers, launch CH341A_c.exe (v1.29) as admin.  Select Type: 25\26 SPI FLASH, Manu WINBOND, Name W25Q32FV. Click Detect and

Hiding Azure Enterprise App from users using az cli or PowerShell

Toggling "Visible to users" setting on portal adds / removes tag called HideApp. Hide app: ~$ az ad sp update --id f5f6ecff-8661-4726-a83f-8e7db8aa068f --add tags "HideApp" "Unhide" app: ~$ az ad sp show --id f5f6ecff-8661-4726-a83f-8e7db8aa068f --query tags [   "HideApp",   "WindowsAzureActiveDirectoryIntegratedApp" ] ~$ az ad sp update --id f5f6ecff-8661-4726-a83f-8e7db8aa068f --remove tags 0 [   "WindowsAzureActiveDirectoryIntegratedApp" ] For PowerShell example see .

How to get list of Azure service tags and IP ranges using az cli

Microsoft provides weekly updated list of IP addresses used by various Azure features as downloadable JSON file on their webpage. Automating download of it is however not supported and prone to breakage. Same information is now also available via Azure Service Tag Discovery API. New API is still in public preview state and list of IPs it provides is far less than downloadble file contains. So either list of IPs from API is tailored for your particular subscription or it is incomplete. Discovery API requires authenticated session to Azure so we need to create service principal and custom RBAC role to keep things secure. See you for more after the break.

RHEL7 / CentOS7 network interface going down once per hour

There's really bizarre bug in RHEL7 / CentOS7. Once per hour NetworkManager will remove IP addresses from ethernet interface after hitting some bug and triggering "link loss" action. Interface may come back by itself or may not. It does come back when you login as root on console as login triggers some repair action part via systemd...

Migrating user accounts from older Linux to RHEL7 / CentOS7

Another pointless change just to break backwards compatibility - RHEL7 and CentOS7 prevent users with uid lower than 1000 from logging in. This is bad when you're migrating accounts from existing Linux server where uids start at 500.

RHEL7 / CentOS7 with sshd on ports 22 and 443

Short version: Not as simple as you thought.

Tracking wired client behind Aruba AP

So you have setup with Aruba RAPs that bridge their wired ports to VLAN on controller. Web interface only tracks wireless clients so you have no idea what AP client with particular IP is connected to.