Tuesday, July 28, 2015

DHCP tricks with Linux network namespace

Some notes from my experiments with fetching more than one IP address from DHCP for same physical ethernet adapter. Nothing too difficult and you don't even need netns for this, few policy route settings would be enough if dhclient (and especially dhclient-script) wouldn't be so broken. For example dhclient has nasty habit of hijacking udp/68 on all network interfaces rather than only those it controls. There's also issues in some cases due routing when DHCP server is not on local LAN but behind WAN like it's in corporate and ISP networks.

Monday, July 27, 2015

Installing Ubuntu 14.04 LTS to Wyse Z90D7 Windows Terminal

I recently posted how to update Wyze Z90D7 to latest available Windows firmware. Which is far from usable. Let's see how Ubuntu works on this hardware. Actual flavour I picked is Lubuntu, but hardware support should be same for all.

TL;DR: What a piece of shit this is, don't waste your time just toss it to bin already.

Friday, July 24, 2015

Updating Wyse Z90D7 Windows Terminal from USB stick

I recently found old decommissioned Wyse Z90D7 Windows Terminal. Old BIOS, messed up OS, etc. So exactly how do I update this thing without all those complex management systems and active Wyse support contract?

Wednesday, July 22, 2015

Crossflashing Huawei B593s-22 from Sonera to Elisa firmware

My B593s had ancient Sonera branded firmware that has DNS issues when IPv6 is active. At least IPv6 reverse queries stall causing long delays. There's some rumors going that Sonera provides updated firmware over-the-air, but I couldn't trigger update despite trying hard. Might be because I was using Elisa SIM card. Since Elisa does have fairly recent firmware available for download I thought why not use Elisa firmware instead - get IPv6 bug fixed, have correct operator settings as default and also future updates should work without extra hacks.

Tuesday, July 14, 2015

"New Skype Meeting" option missing from Outlook 2013 calendar

Clean Windows 7 install with latest Office 2013 from Office 365 and latest Skype for Business 2015 (The Application Formerly Known As Lync) also from Office 365. Problem is that "New Skype Meeting" option is missing from Outlook calendar options. There's just empty space where ribbon bar button should be.

Monday, July 13, 2015

Ericsson (Dell, Lenovo, Panasonic, Toshiba) 3G WWAN modules hanging

Ericsson has manufactured probably millions of faulty 3G WWAN modules that hang after few minutes to few hours of use. There's driver and firmware updates out that may sometimes help but usually only by extending time before hang bit longer.

"Use your Start menu to check for updates" error on Windows 7

If you install IE 11 before enabling "Microsoft Update" feature of "Windows Update" on Windows 7 you'll be stuck with "Use your Start menu to check for updates" error message. Solution is to open IE, then hit ALT to show menus, go to Tools, Compatibility View settings and enable "Use Microsoft compatibility lists".

Wednesday, July 08, 2015

Running TFTP server on Ubuntu 14.04

# Install tftpd-hpa package
apt-get update
apt-get -y install tftpd-hpa

# Fix config file broken by default
# - use correct tftpboot directory rather than random location under /var
# - chroot to tftpboot
# - allow uploading of files but not overwriting existing
# - listen IPv4 and IPv6 instead of IPv6 only
# - enable logging
mv /etc/default/tftpd-hpa /etc/default/tftpd-hpa.old
cat <<'__EOF__' >/etc/default/tftpd-hpa
TFTP_USERNAME="tftp" 
TFTP_DIRECTORY="/tftpboot" 
TFTP_ADDRESS=":69"
TFTP_OPTIONS="--secure --create --listen --verbose"
__EOF__

# Create tftpboot directory and use proper permissions
mkdir /tftpboot
chmod -R 1770 /tftpboot 
chown -R root:tftp /tftpboot

# Restart service
service tftpd-hpa restart

P.S. There's config file bug causing tftpd to listen only IPv6 connections by default... https://bugs.launchpad.net/ubuntu/+source/tftp-hpa/+bug/1448500

Tuesday, July 07, 2015

Smartmontools v6.4 and Ubuntu 12.04

I had to upgrade to new Smartmontools 6.4 on my Ubuntu 12.04 server as old version lacks Prolific PL2773 USB3 to SATA bridge support.