HowTo: Fix slow password prompting when doing SSH logins
You may notice on some systems you build that when you SSH into them, there seems to be a long delay before the system prompts you for your password. In a time-sensitive situation, this gets real frustrating, real fast.
Here’s how to fix it.
HowTo: Create a Diskless workstation that boots from PXE using Ubuntu
Diskless booting is where a PC starts up purely from a network connection. It does not have a physical hard-drive in it to start from in the traditional manner.
Why would you want to do this? Well, say for example you have a MythTV Frontend PC. For the most part, most Frontends are dedicated PC’s connected to a TV or projector that are not used for any other purpose, so technically there is really no need to have a hard-drive inside one as nothing new will ever be stored (all the media is streamed from the Backend server). There’s also the added bonus of less noise by not having a hard-drive installed.
Another good example of using a Diskless boot environment is for performing offline virus scans of Windows based PC’s in a safe environment that is not Windows, using tools like ClamAV. In a corporate environment, having a “normal” installation makes it easier to setup default settings that normally don’t suit booting up from an Ubuntu Live CD, such as corporate Proxy settings. Making a Diskless Boot setup is far easier than creating a customised Live CD in this instance.
So how exactly do you create a diskless booting PC?
HowTo: Automatically determine your public IP address and email it periodically
Let’s say you are running a poor man’s website where you are just testing stuff but have no real intention of buying a domain name or paying your ISP to give you a static IP address.
If you want to access your test site remotely, you need to know your public IP address, however your home ISP gives you a dynamic public IP address and every time you have a power failure, or reboot your router, you are assigned a brand new public IP address. This makes it very annoying if you are testing your site remotely.
Sure, you could use a Dynamic DNS service to keep track of when your public IP address changes, but what if you have a paranoid client who does not want to use even Dynamic DNS? How do you keep track of your new public IP without having to get to your internal network to read it each time?
What you need is a way to be able to have the system send you an email with your current public IP address so that there is no guess work involved. But how do we do this?
HowTo: Get an Ubuntu Live CD to boot off a PXE server
Following my article about creating your own PXE network boot server, here is the first practical use you can put it to – taking the Ubuntu Live CD and turning it into a network-bootable version!
Network booting the Live CD has obvious advantages – aside from booting faster than CD (especially on a gigabit network), it is indispensable as an emergency boot medium in a workplace environment, especially for broken Windows systems, and allows for Ubuntu effortless installations on netbook PC’s that don’t have optical drives and saves you having to have a USB stick handy.
HowTo: Setup your own PXE Boot Server using Ubuntu Server
The Preboot eXecution Environment (PXE) provides a means of starting up a PC using a network adapter instead of the traditional method of hard-drive, USB flash stick, CD or floppy disk.
Why would you want to boot a PC from the network? Well, it opens the door to booting diskless workstations, eg: Internet Cafe PC’s, or if you regularly install tens or hundreds of PC’s, you can start the installer on all those machines at once without needing to have individual boot/install media for each machine. You can even use Linux PXE for starting Microsoft Windows network installers and tools.
This article is going to show you how to setup a standard Ubuntu 10.04 Lucid Lynx Server to respond to a PXE boot request and present a boot menu ONLY. I will put practical applications such as installing Ubuntu over the network or booting a Live CD over the network into separate future articles.
HowTo: Configure Ubuntu to be able to use and respond to NetBIOS hostname queries like Windows does
Users in the Windows world are very used to referencing PC’s via their NetBIOS names instead of their IP address. If your PC has a dynamic IP address (DHCP-assigned) of 192.168.0.12 and its hostname (computer name) is “gordon”, Windows users can happily jump into a command line or an Explorer window and ping the name “gordon” which will magically resolve to 192.168.0.12.
If your host is not configured with a Hosts file entry on your local PC or a DNS entry to associate a name with an IP address, Ubuntu can only use the IP address of that PC to communicate with it which means you have to remember what that IP address is with your feeble grey-matter in your head. Likewise, Ubuntu will not respond to a Windows PC pinging its NetBIOS name because Ubuntu does not use NetBIOS at all by default and so it will ignore such requests.
So how do we get Ubuntu to resolve NetBIOS names like Windows? And how can we allow Windows to ping Ubuntu like another Windows PC? Read on…
