Ping without root — Linux capabilities

On Linux, sending a real ICMP echo (a ping) traditionally needs elevated privileges, because it uses a raw socket. SubnetSlinger is built to avoid making you run the whole app as root.

The basics: in most cases ping just works. If raw sockets aren't available, the app quietly falls back to using the system's own ping program, so you still get results — you generally don't have to think about this.

How to tell: ask the Deputy to show your local interfaces — its local_interfaces output prints a line, Raw sockets (cap_net_raw): yes / no. On Linux this normally reads "no", and that's expected — the app runs unprivileged on purpose, so ping uses the system fallback.

Do you need to grant anything? No — not for ping. SubnetSlinger deliberately keeps the GUI unprivileged (that is what keeps your unlocked Vault key out of reach of other processes), so ping simply uses the system ping program. Do NOT run setcap on the app itself — a capability on the GUI would defeat that protection. The one feature that needs a capability is live packet Capture, and it goes on a separate tiny helper (subnetslinger-capd), never the app: run `sudo ./install-linux.sh` once and it installs that helper into a root-owned system folder (/usr/local/lib/subnetslinger) and grants the capability to that copy only — never to anything in your user-writable app folder.

Good to know: capabilities are a real security control — cap_net_raw lets a program craft raw packets, which is why install-linux.sh grants it only to the capture helper it installs, and nothing else. If setcap isn't installed, install-linux.sh stops and tells you how to get it (libcap2-bin or libcap) — until you re-run it there's no Capture and no system menu entry, but ping and everything else keep working. When in doubt, `man capabilities` and `man 8 setcap` are the authoritative reference.