Install vpn-slice with Homebrew

Project links

• Homepage

Commands and aliases

• vpn-slice

Project history

The project grew out of a long-standing OpenConnect/VPNC architecture in which the VPN client handles the tunnel connection but delegates operating-system routing and DNS changes to an external script, traditionally called vpnc-script.

vpn-slice's README presents it as a deliberate alternative to corporate-VPN behavior that reroutes all traffic through the tunnel. It credits an earlier split-tunnelling tutorial for the basic approach, sshuttle's host-discovery options for inspiration, and a community pull request for cleaner OS-dependent separation and macOS support.

Adoption history

The OpenConnect project documents vpn-slice as an alternative script written by one of the OpenConnect developers, focused on limiting VPN-routed traffic to a specific subset. That gives vpn-slice a recognized niche among OpenConnect users who need client-side split tunneling even when the VPN server or corporate client defaults to full-tunnel routing.

Package listings in ecosystems such as PyPI, MacPorts, Alpine, and FreeBSD ports reflect practical adoption by users who combine OpenConnect with scripting-friendly network setup. Its adoption is niche, but the niche is clear: developers and administrators forced to use restrictive VPNs while preserving local Internet routing.

How it is used

Users invoke vpn-slice as the OpenConnect or VPNC script hook and pass the hosts, domains, or subnets that should be reachable through the tunnel. The tool can resolve named hosts using VPN DNS servers, write temporary host entries, and avoid broad resolver changes outside the VPN slice.

The tool is not intended for privacy VPN use cases where all traffic should go through the tunnel. Its README explicitly frames the use case as minimizing exposure to monitored or filtering corporate VPN networks.

Why package nerds care

vpn-slice is the kind of small Unix networking tool package managers preserve well: one command that fills a very specific gap between a general VPN client and local routing policy.

Its value is highest for people who already know OpenConnect, vpnc-script, route tables, and DNS side effects; for those users it replaces a fragile personal shell-script wrapper with a maintained upstream tool.

Timeline

• 2010s: vpn-slice emerges as a Python vpnc-script replacement for OpenConnect/VPNC split tunneling.
• 2019: Public questions around OpenConnect plus vpn-slice show use in Nix and macOS workflows.
• 2020s: OpenConnect documentation lists vpn-slice as a recognized alternative script for limited-subset routing.

Related projects

• vpn-slice is directly related to OpenConnect, VPNC, and vpnc-script.
• The upstream README also relates it conceptually to sshuttle, whose automatic host lookup behavior influenced vpn-slice's own host handling.

Sources

• https://github.com/dlenski/vpn-slice
• https://pkgs.alpinelinux.org/package/edge/community/x86/vpn-slice
• https://ports.macports.org/port/vpn-slice/summary/
• https://pypi.org/project/vpn-slice/
• https://www.infradead.org/openconnect/vpnc-script.html