Archives for May 2014

May 29, 2014 By Jared Heinrichs Leave a Comment

Convert .aif to MP3 for free – A complete tutorial with Screenshots

When I first started on this journey of converting aiff files to mp3s almost every converter applications that I tried had some sort of extra programs that would take over your browser.

First off you will need to download WinFF. WinFF is an Opensource absolutely free application with NO spyware, No Crapware etc in it. WinFF is a gui front end that also installs the command line program FFmpeg. FFmpeg is the program that will do all the heavy lifting.

First you need to click on add. select all the files you want to add to the conversion list. Make sure you set the output details to your needs.

When done hit the convert button and voila! Everything is converted!

Yes! it really is that easy to convert .aif to MP3 for free! Let me know if it worked for you.

May 26, 2014 By Jared Heinrichs 1 Comment

Cisco IPv6 Autoconfig CCNA lab notes

This lab will go over IPv6 autoconfig. I will go step by step and show you using commands what happens at each step. I will use a few technologies so that you can see what happens.

I will use a few terms it’s a good idea you understand what they mean:

IPv6 Address – Unlike IPv4 where the IP address and Subnet Mask is separate. IPv6 combines both parts into a single address. All IPv6 addresses can be broken into two major parts.

Routing Prefix – This is essentially like the subnet mask in IPv4. (First 64bits)
Interface Identifier – This is essentially like the IPv4 IP address. (Last 64bits)

Global Unicast Address – Public Routable IPv6 address. It typically starts with 2000::/3. This gives us the ability to use the range “2000::/3 to 3000::/3” of ipv6 addresses.
Link Local Address – These addresses start with FE80::/3 and is a reserved ranged. All IPv6 Enabled Interfaces have Link Local Addresses. These addresses never time out and are used by neighbour discovery or when no routers are present.
EUI-64 – This allows a machine to take its mac address which is 48bit and convert it into a 64bit Interface Identifier. The rule you need to remember is the 7th bit gets flipped and you insert “FFFE” in the middle. I will go over this more later.
Autoconfig – This is kind of like DHCP but can’t provide things like DNS servers and other info DHCP can give out. It can however allow a device to get an IP address as well as the default gateway.
ff02::1 – All nodes in an IPv6 network will join this multicast address
ff02::2 – All routers in an IPv6 network will join this multicast address

Please make sure to read these items. They will be heavily referenced throughout the post. In fact I will sometimes ask you to come back and verify what I said.

The lab will look like this:

What we will do:

On R1 will be manually configured the Routing Prefix on f0/0. Because this is a lab we’ll use EUI-64 to automatically configure the Interface Identifier of the Global Unicast IPv6 address.
On R1 we will assign an IP address of 2001:1::1/64 on f0/1
We will turn on IPv6 routing
On R2 we will tell f0/0 to use Autoconfig. Using multicast it will find out things like it’s IPv6 and default gateway “auto-magically”.
On R2 we will assign an IP address 0f 2001:2::1/64 on f0/1
We will turn on IPv6 routing

R1

Right off the hop let’s do a “show ipv6 int brief”. You will notice both ports are Administratively down. The both do not have any IPv6 addresses applied to them.

Notice there is no Link-Local Address on either of the interfaces! One thing that confused me when I first started looking at Cisco devices as compared to Microsoft devices is that Windows just “magically” created Link-Local Addresses. Why doesn’t Cisco devices do the same?

Well it turns out that Microsoft has enabled IPv6 on every interface by default as we can see here:

If we were to un-check the IPv6 and reboot the computer, the computer would no longer make a Link-Local Address because IPv6 is no longer ENABLED on that particular interface. In essence it would be similar to how Cisco routers work out of the box.

So what is the equivalent command on Cisco devices then? From what I can gather there is 3 ways to get a Link-Local address on the router.

1.) Enable IPv6 on the interface:

To enable IPv6 on a particular interface just go into the interface config and type “ipv6 enable”. Look at the output and see how the Link-Local address get’s automatically created.

2.) Configure a Global Unicast Address on an interface

Because IPv6 requires all ports to have a Link-Local Address when you assign a Global IPv6 address to an Interface, Cisco will automatically enable IPv6 for you in the background. It’s this process that makes the Link-Local address similar to option #1.

3.) Manually enter a Link-Local Address

So if you don’t want the router to create a Modified EUI-64 address and want to manually create a link local address you would need to type in these commands. Notice the IPv6 Link-Local and IPv6 Prefix? The IPv6 Prefix is when you want to enter the Global Unicast Address.

Before we apply the IP addresses we should really run a command to verify that this router hasn’t joined any IPv6 Multicast Groups.

To see what groups an interface has joined you need to type the command “show ipv6 int fa0/0”

The command brings back absolutely nothing which is to be expected! IPv6 hasn’t been enabled yet!

4.) Apply Global Unicast Address

Because we want to do as little typing as possible let’s enter the Global Unicast address as per the lab layout. Doing so will automatically enable IPv6 on that interface and automatically create our Link-Local Address:

int fa0/0
ipv6 address 2001::/64 EUI-64

Let’s verify that the router took the command. We will run another show ipv6 command:

Just as we expected! Both the Link-Local and the Global Unicast IPv6 address show up! Great! You might have wondered why I got you to run that “show ipv6 int fa0/0” earlier. Well let’s run it again now that we enabled IPv6 on this interface!

Notice how the interface has also automatically joined multicast FF02::1 address? Go back up to the top of this post. All nodes in a network will join this node! The router did just that.

NOTE – Please notice the Multi-cast joined groups one more time before you proceed!

Let’s actually enable the interface port now.

Notice the interface has now added one more Multi-cast group to the list! Does this address look a bit familiar? It should! The Multi-cast address is made from the Link-Local address. The last 24bits of the the Link-Local address to be precise! “D4:0000”.

This router CAN’T route IPv6 traffic as it stands. Similar to IPv4 you can enable and disable a router’s ability to route traffic. Cisco by default has disabled IPv6 routing.

We will type the command in global config mode “ipv6 unicast-routing”. Yup. That’s all it takes to enable routing!

Let’s re-run the show ipv6 int fa0/0 command we ran earlier and see if anything has now changed!

The router has now become part of the Multicast group FF02::2. This should be expected because we just turned on IPv6 routing on the router. All routers will automatically join FF02::2 and we just proved this!

We’re now done on R1!

We don’t need to cover as much in this setup because we went over so much with R1!

On R1 let’s first make sure there is no IPv6 addresses, and then tell it to autoconfig itself.

Because R1 is a router and is on the same network as R2, R2 will use multicast to ask for an address. We see that the R2 router received a Global Unicast Address from R1 using the Multicast address FF02::1. We can also see once we enable the interface that R2 even configured that R1 is it’s default gateway!

We really should turn on Routing as well since this is a router! Let’s do it now. We will need to use the command “ipv6 unicast-routing” similar to what we did on R1. Again let’s run a “show ipv6 int” command to verify that the router has joined the router Multicast group FF02::2.

We can see it did! Well done. Everything is all setup!

May 25, 2014 By Jared Heinrichs Leave a Comment

Cisco – How to show Mac Address of Interface

There are a few ways of getting the MAC address into from a Cisco device. The option to get a MAC address that requires the absolute least amount of typing is:

en
conf t
show int fa0/0

This will spew a whole ton of info. The only issue with this option is there is too much info and sometimes finding what you are looking for is harder than it needs to be.

My prefered way of getting the MAC address of the interface is by using this command.

en
conf t
show int fa0/0 | in Hardware

Let’s go over the last line shall we? It reads… Show interface Fa0/0 … Take that info pipe it.. and display the info in Hardware section.

Like I said earlier I much prefer the last output. The only gotcha is making sure that you use a “H” instead of a “h” in “Hardware”. Case DOES matter!

May 24, 2014 By Jared Heinrichs Leave a Comment

Night Photography Basics

Night photography, or astrophotography, is easier than you may think. It really boils down to a little planning and knowing a thing or two about how a camera works.

Here is a simple guide to capturing shots of the night sky, and some simple tips and tricks that will open up a whole universe of potential for anyone with a camera and a tolerance for late nights under the stars.

The basics

While a camera with manual controls, a fast wide lens, RAW capabilities and a big sensor does make a big difference, stunning night sky shots of meteors, the Milky Way and star trails can be captured using just about any camera these days.

Equipment aside, here is what you, the aspiring star shooter, need to know.

Night sky shots can be lumped into two main categories:

Shots where the stars appear as stationary specks or points of light.
Shots where stars appear as streaks, taking advantage of the rotation of the Earth.

To capture meteors (or the Milky Way), exposing for points of light is generally best because it allows the shooting stars to track across the frame — an effect that requires the camera to remain totally still and the exposure time relatively short.

The 500 Rule

The wider your lens, the longer you can leave the shutter open without turning stars into streaks.

A handy but rough tool for figuring out how to avoid noticeable blur, or unwanted star trails, is the 500 Rule. Take the number 500 and divide it by the focal length of your lens (whether it’s a digital SLR or a point and shoot, this is typically displayed in millimetres). The result is the maximum time in seconds before trails will appear.

For example, a 14 mm lens gives you a maximum exposure time of 36 seconds. A 24 mm lens allows you a 21-second exposure, and so on.

A Perseid meteor flashes across the constellation Andromeda during the 1997 incarnation of annual August spectacle. The one-off Camelopardalid meteor shower Friday night could put on a ‘very nice display’ comparable to major meteor showers such as the Perseids, astronomers say. (Rick Scott and Joe Orman, SkyandTelescope.com/Associated Press)

Note that because camera sensors have improved, the traditional 500 Rule is no longer one-size-fits-all, and you may see it referred to as the 450 or 600 rule, depending on your camera. But 500 can still be used as a rough guide, then you can experiment to see what works best for you.

If your camera lets you adjust the aperture, you can do some more fine-tuning. Combined with an aperture of 2.8 (remember, the smaller the number, the bigger the aperture hole and the more light the lens is allowing to pass through to the sensor) and an ISO setting that isn’t introducing too much grain into the image (let’s just say somewhere between ISO 3000 and 6400, which is generally safe on most modern dSLRs and point-and-shoots), the 500 Rule should yield a pretty satisfactory first frame.

From there, you will need to fine tune based on what looks good to you, the amount of ambient city light affecting your shot, and the characteristics of your particular camera.

While its easy to get bogged down in the technical aspects of camera settings and exposure times, keep in mind that the most significant factor when shooting the night sky, or anything, is light. All you can do is control how much or how little light reaches the camera’s sensor. Shooting is like cooking and the amount of spice is up to you.

The darker the better

Getting away from bright city lights will dramatically increase the chances of getting a crisp, dark sky against which the stars will really pop out.

Use a heavy tripod with a locking ball head to keep the camera as still as possible during the exposure. You don’t want a shaky camera blurring the stars, so this means no holding the camera in your hands while you’re shooting.

Don’t have a tripod or a bulb-release to trigger the shutter?

Make a small sandbag out of an old sock or use a shoe as a support. Even a pile of rocks or the ground can work really well to prop your camera at the right angle to catch the patch of sky you’re after.

Using your camera’s timer function, frame up the shot as best you can, hit the shutter, put the camera down on the support (or back away from the tripod), then wait for the click before touching the camera and checking your capture.

Many cameras, including most dSLRs, allow for exposures up to 30 seconds — plenty of time to capture the night sky and, if you’re lucky, a shooting star or two will have streaked across the frame.

If its a meteor shot you want, employing the 500 Rule to get the maximum exposure time without trails in combination with a high rate of fire increases your chance of capturing a shooting star, or several. An interverlometre (basically a timer sold separately for most major camera brands, or sometimes built-in to the camera and accessed through menu settings) will allow you to shoot continuously without touching the camera.

Star trails

To get a circular effect in the stars in your photo (taking advantage of the rotation of the Earth), look for the ‘B’ for bulb release on your shutter control dial (or in the manual control settings of many new digital point and shoot cameras). Use that setting with an old-fashioned bulb-release cable (or your interverlometre) to hold the shutter open as long as you like.

A higher f-stop or aperture, or a lower ISO setting, can come in handy here if you are after a shot of the stars completing a full rotation or stretching all across the frame.

A cool technique for star trails is to focus on the North Star, Polaris, and to keep the shutter open for several hours such that the stars appear to trail in a full circle around the fixed point.

There are also techniques involving shorter exposure times (employing the 500 Rule) and editing software to ‘stack’ dozens or even hundreds of images taken over several hours to give the appearance of movement in the stars. This technique will allow for a final image that includes both star trails and shooting stars.

Quick recap:

1. Get to a dark location, away from sources of starlight-killing city lights. The Dark Sky Finder is a handy tool for determining how far off the beaten track you’ll need to get.

2. Keep your camera steady with a solid tripod. Shooting at night requires holding the shutter open longer — for several seconds, minutes or even hours — as opposed to the 10ths or 100ths of a second needed for your typical daylight shot.

And to find out the best angle to capture the sky from any point on the planet, download the Photographer’s Ephemeris.

Happy shooting.

May 23, 2014 By Jared Heinrichs Leave a Comment

How to view IPv6 joined Multi-cast groups in Windows

I am working on some cisco certifications and find viewing joined IPv6 Multi-cast groups is very easy. To do it on a Cisco router just type:

show ipv6 int gig0/0

NOTE – [You might need to change the gig0/0 to what ever interface you need]

In windows you need to run a net shell command to view what IPv6 Multi-cast groups have been joined. The net shell command is:

netsh int ipv6 show joins