Afternoon all,

Got a fairly techical question here for anyone that may be able to help.
As most of you know IPv4 is old fassion now. My company wants to start using IPv6 in new networks featuring Domain / Terminal servers and eventually basic Peer to peer sites. Trying to figure out a good method of assigning machines local IPv6 addresses is posing quite a problem. Nothing technically wrong besides knowledge in the aspect of IPv6 configurations.

Another tech and I have figured out the basic non-routable configuration for IPv6 and understood it. What we are having a problem with is the 40bit's after the initial 8bit's.

| 7 bits | 1 | 40 bits | 16 bits | 64 bits |
+--------+---+--------------+------------------+--------------------------+
| Prefix | L | Global ID | Subnet ID | Interface ID |
+--------+---+--------------+------------------+--------------------------+


The Global ID is what we are having a problem with - You need to use an equation to work out what this global ID will be.
Here is the equation:
1. Obtain the current time of day in 64-bit NTP format
2. Obtain an EUI-64 identifier from the system running this algorithm
3. Concatenate the time of day with the system-specific identifier in order to create a key
4. Compute an SHA-1 digest on the key; the resulting value is 160 bits
5. Use the least significant 40 bits as the Global ID
6. Concatenate FC00::/7, the L bit set to 1, and the 40-bit Global ID to create a Local IPv6 address prefix

I tried looking for a program that will work this out for me with no luck.
This is the information I am working with at the moment:

" The allocation of Global IDs is pseudo-random [RANDOM]. They MUST
NOT be assigned sequentially or with well-known numbers. This is to
ensure that there is not any relationship between allocations and to
help clarify that these prefixes are not intended to be routed
globally. Specifically, these prefixes are not designed to
aggregate. "

Can anyone shine some light on this for me?

Just a side question, why are you looking at ip4 for internal?

Surely you'd be better of sorting out IP6 externally and migrating to IP6 internally when needed, which you might not even need to do.

I don't even get why you need to understand the protocal at that level anyway? What are you trying to do, in application terms? Or are you writing your own drivers or something?

IMO, get an ipv6 prefix, and allocate all of your machines a proper IPv6 address instead of d***ing around with private ips. In other words, use globally routable addresses. Otherwise you may as well just stay with v4.

IMO, get an ipv6 prefix, and allocate all of your machines a proper IPv6 address instead of d***ing around with private ips. In other words, use globally routable addresses. Otherwise you may as well just stay with v4.

We haven't confirmed this yet but we are fearing a problem with site to site private connections when it comes to using this..

We basically need to statically set all machines on every network to give us the management and usability we want.

if you have the mac address of the machines in question you should be easily able to find their autoconfigure'd IPv6 addy

Yeah, think I was looking at it all wrong.. Thanks all!

I guess what I'm most worried (for lack of better words) is that if I don't stick to the standard and use (for example) a part of the PC's MAC address for the global ID and that just happens to land on the same as someone using what the standard SHOULD be that may make people angry.. Haha.