Archive for the ‘Uncategorized’ Category

Streaming from an underwater camera with a Raspberry Pi

Among this summer’s projects was getting an underwater camera online and streaming. The camera is placed within a fishing device designed like a cage, called Kjærra, dating back to the 14th century. The trap has a one-way entry; the fish enters the cage and can’t escape, and is subsequently extracted from the cage. When the […]

MikroTik configuration revision control with rancid

The config revision control tool rancid (Really Awesome New Cisco confIg Differ, but not at all limited to Cisco devices) has proven extremely useful. Rancid notifies you if there’s been some changes to a device, and since it’s Subversion backed it’s easy to extract full configurations in case you need it. Rancid has been supporting […]

Securely managing multiple Mikrotik units with dsh

dsh is a nice Unix/Linux tool for managing multiple systems efficiently, and I’m using it both at home and at work. In some distributions dsh has been replaced by pdsh, but no worries, pdsh is dsh compatible. Since all MikroTik devices running RouterOS might be managed over SSH, why not use dsh to manage these […]

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Using BOPM with InspIRCd

Using Blitzed Open Proxy Monitor (BOPM) with a fairly new version of InspIRCd needed a slightly different configuration than suggested here and there. The following is working for me, using InspIRCd 2.0.9 and the BOPM package provided by Ubuntu (Lucid, but shouldn’t make much of a difference). First of all, the BOPM service wasn’t granted […]

Reaching multiple instances of the same IP address

A friend recently presented me with the following challenge: Configure a system through which several appliances, all of them having an identical, non-routable, default IP configuration, can be reached simultaneously. All appliances are preconfigured with an IP address of 192.168.1.1 and they had no routing configuration enabled. Yet they should all be reachable over the […]

Path MTU discovery ICMP messages

This is more for my own reference… After configuring my ADSL modem to run i bridge mode, it seems I’m running into a few path MTU issues. To identify any path MTU messages, I’ve been analyzing the traffic on the outside interface looking for path MTU issues using the following tcpdump syntax: tcpdump -n -s0 […]

Avoid hotlinking with Varnish

There’s a quite a few articles on how to configure Apache to avoid hotlinking, so that material on your web server isn’t used on remote sites (at least not without your knowing). This is how to do the same with Varnish. The example suggests that you forbid hotlinking to anything under http://www.example.com/fun/. The code will […]

Spanning-tree on Linksys srw2008

After finally admitting defeat I had to boot into Windows for managing my Linksys SRW2008 switch through its WebView, the reason being I could not find out how to enable regular spanning-tree on the switch. Having enabled it through its IE-specific web UI, I logged in to the (rather poorly documented) CLI afterwards to check […]

GeoIP and MySQL

For my own and possibly others’ reference, these are quick notes on how to use GeoIP data from MaxMind in their new split file formats. Older tutorials describe using the GeoIP data from a time when they were one file, it seems now MaxMind have split into two files. The files are split into Location […]