Friday, September 16, 2011

IPv6 on Windows XP

Back on June 21 I posted about IPv6 teredo interface not working on Windows 7 and how to correct this using commmand prompt netsh commands.

Just in case anyone is having the same problem on Windows XP, here is the solution for it. The problem is the same, the commands are slightly different.

Command for showing the teredo interface state:
netsh interface ipv6 show teredo

If it says the state is offline with error of none, try this:
netsh interface ipv6 set teredo enterpriseclient

That should do it. The IPv6 network components were incorrectly thinking your computer was in an enterprise situation.

Thursday, September 15, 2011

Looking for a Packet Flooder?

Check out the video on youtube after you read this post.

We have noticed that many people looking at our Packet Generator got there because they were looking for a 'Traffic Generator' or a 'Packet Flooder' - but found that the Packet Generator is really not capable of filling an interface up to the bandwidth they want. They now have their wish. And it works with IPv4 or IPv6.

NetScanTools Pro v11.10 (not released yet) has a new tool called 'Packet Flooder'. It can generate UDP packets at a very fast rate using multithreading. The packet payload can be either random numbers or alphabetical 'abcdefg' etc. The payload length can be random or fixed. The target port can be random or fixed.

Another new thing you may notice is the bandwidth gauge and historical chart. You are going to see more of these in future versions. The gauge shows the real time bandwidth utilization and the historical chart shows it over time.


Saturday, September 3, 2011

Labor Day Sale

This weekend and through Tuesday Sept 6, 2011 we are having a Labor Day Sale. The biggest discount is NetScanTools LE - 62% off. So instead of $129, it's now $49 this weekend only. We also have a 25% discount on NetScanTools Pro installed or USB, the Managed Switch Port Mapping Tool, ipPulse and the Pro/Switch Port Mapper bundle.

Drop by and check out the savings.

Have a great holiday weekend!

Friday, September 2, 2011

IPv6 Link Local Addressing

As I've been working to adding IPv6 capabilities to NetScanTools Pro. As I have worked with link local addressing I have learn some interesting things. In the IPv4 world if you want to ping an address or connect to a computer on your local network, the software can easily find out the best interface (if you have more than one) to send packets out of to the other computer - all you had to do was supply the IP address. It does this using routing tables and ARP.

In IPv6, it's not quite so easy. In Windows or any other OS, you will often have two or more interfaces capable of talking IPv6. Since all link local addresses begin with FE80:, there is no method for saying this one address is on this segment and this one is on that segment like there is in IPv4 (by using IP address and subnet mask).

Essentially you have to tell the software you are using which interface to use to get to the link local address. If you have one interface to your switch and all the other devices are on the same VLAN, then it's pretty easy. You do this by appending a %# where # is the IPv6 interface number in Windows - also called the Scope ID. In unix derived operating systems like Ubuntu or OS X Lion, you would use %eth0 for the main interface.

How do you know which interface to use? That's where you have to know your network. In my case, this particular XP machine assigns '6' as the Scope ID - you can see this using ipconfig /all. It could be any number, but it's usually a single digit. So to ping an IPv6 address you would enter smoething lik "ping -6 FE80::3CC0:1%6" on the command line (no quotes). Or if you were using NetScanTools Pro v11 Ping Enhanced you would enter FE80::3CC0:1%6 as the target. If you leave off the %6 or change it to another number the software will not know which interface to send the packets out of. In NetScanTools Pro, you will see an error message. The command line ping will tell you the net is unreachable if you use the wrong Scope ID.

Just a few things I've learned about IPv6 link local addressing.