Introduction to IPv6

ipv6

Internet Protocol version 6 (IPv6) is the next generation of the Internet Protocol that was designed to be the succeesor to the current Internet Protocol verion  4 (IPv4).  It was designed by the Internet Engineering Task Force (IETF) to deal with the exhaustion of IPv4 addresses.

An IPv6 address has 128 bits (2128 = a number too large for human comprehension) compared to an IPv4 address which has 32 bits (about 4.3 billion  unique addresses (232 = 4,294,967,296).  IPv6 address is too long; it is quite difficult to handle considering the fact that we are having  problem communicating IPv4 address to other people.

IPv4 has the simple form of four octets or groups of decimal  numbers seperated by periods: 1.2.3.4.  Now try and imaging if we keep that same format for IPv6 address; we’d have: 1.2.3.4.5.6.7.8.9.10.11.12.13.14.15.16 –  it would be way to long and too difficult to remember.  So our friends at the IETF decided to shorten it by breaking the IPv6 address into eight  16-bit  groups and switched to Hexadecimal numbering scheme with each group separated by a colon.  So a  typical IPv6 address now looks like this:

2000:F53A:0000:0000:0F14:0000:0000:0053.

Even with that, it’s still way too long so they decided shorten it further by removing the leading zero’s.  The aforementioned address could be represented  as: 2000:F53A:0:0:F14:0:0:53.  As you can see here, all the leading zero’s are removed and if any group of number has four 0’s, it’s replaced by a single 0.   If that isn’t confusing enough, IETF decided that they want to shorten IPv6 address further by replacing two or more consecutive groups of 0000’s (or 0:0 for  the short form) with a “::” leaving just the double colons between the groups.  So the same IPv6 address above can be represented as 2000:F53A::F14:0:0:53.   If you haven’t recognized it yet, we replaced “0000:0000:” with “:” right after F53A leaving “::” between F53A and F14.

Now you might question why the second consecutive groups of 0000’s didn’t get replaced; that’s because the our friends also said that you can only replace one  consecutive groups of zero’s and it’s gotta be the first occurence in the event that the two groups are of equal length.  The reason they do that is to  guarantee that we can reproduce the fully expanded address correctly.

To demonstrate that point, let’s the the same address above and modify it a little bit: 2000:0000:0000:0000:0F14:0000:0000:0053.  Now if we remove the  consecutive groups of zero’s, we’d have: 2000::F14::53.  Without the rule above, we can’t correctly reproduce the original address.  Let’s break it down:
By looking at 2000::F14::53 we know that we have three groups of and need five more to form a complete IPv6 address.  But do we put two groups of 0000’s  or three groups of 0000’s at the first occurrence of the “::”?  So to remove this ambiguity, the rule states that we can only have a single “::” in  any IPv6 address.

To summarize, IPv6 is the next generation of IP address; it is 128 bit long and resulting a really large address space – we won’t be running out of address for quite some time to come.  IPv6 address can be written in various formats with leading zero’s can be removed from each octet.

If you want to experiment with various ways to represent IPv6 format or to subnet it, check out this site.

Using PortScanner Feature in Pinkie More Effectively!

Another must have tool for a network professional is the Port Scanner. It is used to probe a host to see if host is listening on the specified port (open) or not.

Here’s how you can use PortScanner in Pinkie:

  • Scanning Default Ports: To scan the default ports, enter an IP Address, check the Default Ports checkbox then click on the Start Port Scan button.
  • Stop Port Scan: To stop a Port Scan in progress, click on the Stop Port Scan button and in a few seconds it should abort the scan completely.
  • Scan Ad Hoc Ports: To scan a host on an ad hoc basis, enter an IP Address, check the These Ports checkbox, enter the port numbers (separated by “,” & “;” for each port number or by “-” for a range of ports) then click on the Start Port Scan button.
  • Change Default Ports: Default Ports setting can be changed in the Settings Menu. Press F5 to bring up the Application Settings dialog then click on PortScanner tab. Enter new ports as you see fit.

PortScanner can still use a couple of enhancements. If you need something more specific, send in your request now.

Using PingSweep Feature in Pinkie More Effectively!

PingSweep has been added to Pinkie since v1.08. And over the years, it’s been fine tuned and enhanced quite a bit.

Below are some tips to help take advantage of all the useful enhancements in Pinkie’s PingSweep feature:

  • Sweep a Subnet: To sweep a subnet, enter an IP Address, then select a subnet mask. Pinkie will automatically scan the subnet and also does DNS lookup for the addresses being scanned.
  • Sweep a Specific # of IPs: To sweep X number of address, enter the start Host Address then enter No. of Hosts and click on Start Ping Sweep button. Pinkie will scan from the Host Address up to X number of hosts and also does DNS lookup for them.
  • Copy PingSweep Result: At times, you might need to send the pingsweep result to someone else. To do that, just do an pingsweep then click on the Copy to Clipboard button. After that, you can paste it into your email or whatever application at your choosing.
  • Include Only Live Hosts: Check this option only if you want to copy the live hosts or those that responded to ICMP request.
  • Copy a Single Address: Click on a particular row in the result listview will copy its IP Address to the clipboard. I find this function is particularly useful when someone asks me for an IP Address that hasn’t been assigned.

There are some other enhancements in the works for PingSweep. Hopefully they will make it to the next release.

As always, if you need to enhance the PingSweep function to suite your need better, send in your request and I’ll check it out.

Using Subnet Calculator in Pinkie

Subnet calculator is a must have tool for a network professional. Pinkie’s Subnet Calculator is unique in a way that it captured both IPv4 & IPv6 information in the same user interface.

IPv6’s adoption is slow partly because it’s complex, confusing and not something that one can remember easily compared to IPv4 address. Pinkie’s SubnetCalc is meant to help with IPv6 adoption by exposing IPv6 to you plus it gives you more information about IPv6 in hope that you can broaden your knowledge.

Below are some of the enhancements that were built into Pinkie:

  • Working With Subnet Mask: If you prefer to work with Subnet Mask, the dropdown box give you the option to choose subnet mask which also displays the CIDR notation.
  • Working With Prefix Length: If you prefer to work with the prefix length, the textbox named Prefix Length allows you to enter prefix length directly. This is how you can subnet an IPv6 address.
  • Related IPv6 Info: When you are working with IPv4 address, Pinkie will give you all the details like Network ID, Broadcast ID, Wildcard Mask, Block Size… and it also gives you the extra details about related IPv6 info – useful information to make the transition over to IPv6 easier.
  • Related IPv4 Info: Like wise, when you are working with IPv6 address, Pinkie will show you the detailed IPv4 information when applicable. This is done automatically. No user interaction is required.
  • Show Various IPv6 Notations: The checkboxes in the Display Options group box allows you to see IPv6 in multiple forms. Check or uncheck them to see the changes; maybe then you’ll know why IPv6 is sort of confusing at first glance.
  • IP Address Examples: The dropdown box at the bottom of the SubnetCalc tab can show you different IP address examples from IPv4 to IPv6. If you select an IP address example and click on the Tell Me More link, Pinkie will take you to the web where you can learn more about that particular type of address.

There are so many variant of IP Subnet Calculator. I try my best to bring what I think is important into Pinkie’s SubnetCalc. If you have a particular enhancement for it, feel free to send in your suggestion.