Openconnect on RHEL7

Background

Customers who let you do remote work will most likely not have internet-accessible servers (probably for the best). If you’re lucky, you’ll be able to VPN into their network, or at least onto a bastion host to get to other machines. Otherwise, the worst case scenario is you’ll have to use some sort of virtual remote desktop, or a Citrix web-client.

I’ve found that using the open source openconnect client is probably the most hassle-free approach for connecting to VPN on RHEL/Centos/Fedora (many distros). It saves you the headache of all the CNTLM hackery, installing Cisco Anyconnect, or whatever magic you need to get it to work.

Installation

First, you’ll need to make sure openconnect is installed, or install it if it’s not…

sudo yum install -y openconnect

You then connect with the following. The actual flags required will be different depending on what the VPN server requires. The good-ole-man pages is still the best place to find out more.

sudo openconnect -v vpn_host_address -u username

Unless the VPN server has publicly issued certificates, you’ll probably get a warning about connecting to the server for the first time.

You can pass in this flag if you want to suppress that warning --servercert sha256:XXXXX

Other than that, it’s super easy to fire up a terminal and start a VPN connection. You can take it one step further and create a script that does all the legwork for you. It might not be 100% script-able if you need to enter a PIN+OTP, but at least it’s less commands to type.