As part of my work, I often find technical challenges that I am unable to find a resolution in the time I have but have otherwise worked around. This page is to collect such interesting challenges for eventual resolution, either by myself or by any interested party who sees this.

Cisco ISO: How to get a Cisco Router to send a DHCP Release packet to the server that it got it's IP address from. As IPv4 addresses are in short supply, most ISPs giving out just one public IP do so through a dynamic means, but if the ISP's DCHP server messes up we need a method of getting another address by telling their server we don't want that one. Apparently there was a Solution, but link rot got us before I could save the details locally.

Linux BASH scripting

How to tail the last X minutes of a log file? Where those X minutes sometimes have zero lines and sometimes hundreds of lines.

How to tail all lines past a specific string?

Test if 'in the last X lines of a log' (aka tail -n 200)
        (stringA appears but not stringB) or (stringA appears only after stringB)

This page was last updated on 2014-09-19