Working with Firewalls and Microsoft Products it is sometimes necessary to allow certain endpoints in your firewall. Unfortunately not all are available through their provided Azure IP and Office 365 IP lists.

They are only available as either a list in …

Photo by Compare Fibre / Unsplash

Hi i tried to publish the syncthing WebGUIs from my DMZ systems to my internaly accessible haproxy VIP on my pfSense firewall and couldn’t figure out WHY I can’t connect to the service, it seems to have error “503 Server not found” until I choose to use the default backend.

I was stuck for half an hour, this moment as I write this blog entry. I figured out:

HAProxy refers to the first match of the acl per IP in the frontends, NOT WITH THE PORTs in mind. I had to use a different ACL check that matches only this frontend I wanted.

Today I had the problem to restrict my ZeroTier network down to the device administering and the device providing.

What does that mean ?

I wanted to restrict my ZeroTier networks so potentially compromised devices do not get to connect to other devices, like network isolation rules. For instance I…


I’ve missed an auto-snapshot feature for my proxmox installation, automated backups are possible.

But I rather would like to instant restore a vm than retrieving a backup, at least for the first 7 days.

Because I run backups only on weekend to the storage server.

Here is my code for it:

Originally published at on September 3, 2020.

Piere Wöhl

#infosec, #emsland, #introvert, #nerd, #blueteam

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