Friday, February 22, 2013

Activating extroot on OpenWrt 12.09-rc1

Enabling extroot on OpenWrt 12.09-rc1 is bit tricky. Likely reason you're trying to enable extroot is lack of free space i.e. router with 4MB flash. Problem is that unless you're interested in creating custom firmware images there's no space left for tools to enable extroot using old procedure. Following has been tested with TP-Link MR3220 v1. It's ar71xx with 32MB RAM and 4MB flash being lowest end of currently supported OpenWrt compatible devices.

Tuesday, February 12, 2013

Multipath OLSRd (SEREADMO)

Some years ago patch for OLSRd v0.5.6-r2 surfaced that added support for loadbalancing single flow over multiple paths. Documentation on how to set it up is scarce. I did get it working to some extent. It's somewhat unstable and doesn't really like single mesh node having multiple network interfaces, but it does loadbalance traffic over multiple paths as promised.

Monday, February 11, 2013

Measuring one-way network latency, jitter and packet loss on Linux

Ping can tell you round-trip or two-way latency, but if you want to know if it's upstream of downstream that's slowing down you need something else. You need OWAMP (One-Way Ping).

Compiling ntp v4.2.7 for Ubuntu 12.10

Compiling ntp v4.2.7 for Ubuntu 12.10

Saturday, February 09, 2013

Dumping process memory in Linux

Sometimes when troubleshooting misbehaving applications having complete dump of process memory comes handy. Here's small script that does exactly that on Linux. Run it with pid of process you're interested as parameter.

Wednesday, February 06, 2013

Replacing WLAN card on HP nc6000 laptop


Atheros WLAN card on my hack laptop HP nc6000 died sometime ago. No problem I thought as I had unused Intel 2200BG. After swapping card I was greeted with 104 unsupported wireless network device error. While 2200BG was one of original options for nc6000 one I installed had wrong PCI subsystem ID. Quick googling showed multiple people killing their nc6000 after flashing hacked firmware requiring soldering iron and eeprom programming device to recover. Nothing wrong with that and that most certainly has higher hack value, but not for me this time. Since card itself was ok for BIOS I started thinking if I could somehow change ID supplied by card to one HP BIOS accepts...