I'd like to use setfacl so that anyone in group 'app' can edit any file contained within /usr/local/users/app regardless of what the traditional UNIX permissions say. I have two users john and ben. I tried to follow the instruction from another question, but john is not able to write to some files. It looks like this is because of the acl mask.
If I understand correctly, the operating system gets subnet mask together with IP and other stuff from the DHCP server. And this subnet mask seems to be important for router because it knows if packet goes from/to LAN or should be sent somewhere else or it's received from Internet. But why is the subnet mask needed for the operating system?
I have a web app that is hosted on Linux cloud servers (Linode, specifically). I am working with a new client that needs to set up a VPN tunnel between their network and one of my main servers. For this reason, they said they needed a private IP and associate subnet mask, and this IP must be bound to eth0:0.