firewalls Archives

Three Failings of Virtual Appliances

March 12, 2012 by Bob Plankers

I’m torn when it comes to virtual appliances. I love them because they make a lot of installations absolutely brainless. I hate them because the people that create them make assumptions that are ridiculous and unsupportable. Here’s the three ways I hate them the most: 1. There’s no good way to back them up. For organizations that haven’t gone the “whole VM” backup route there are very limited choices for backing these things up. Sometimes the virtual appliance has some method to export the configurations and data, but often not. And when there is a method it’s usually a web interface that cannot be automated. What I want: virtual appliances should be able to export their configuration and data on …

Keep SSH Sessions From Disconnecting

November 3, 2011 by Bob Plankers

With the installation of new firewalls at work I’ve been getting disconnected a lot from hosts I SSH to, due to changes in the inactivity timeouts. It’s particularly inconvenient when I’m tailing a log that hasn’t changed in a while… and then the connection dies, and I don’t notice. Oops. It also happens in various other situations, like NAT through a home router, too. Let the connection sit for a while and you’ll have to recreate it. I could ask our network guys to change the timeouts, but it turns out there’s a better fix from the client side. SSH protocol version 2 supports server keepalive, essentially NOOPs sent to the server to keep the connection up. You can do …