Mailing List Archive: nsp: ipv6

Manual Configuration of Interface ID

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chad at onr

Dec 20, 2010, 8:05 AM

Post #1 of 7 (1345 views)
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Manual Configuration of Interface ID

Hello,

We are deploying IPV6 to our customers and are carefully planning the architecture of how we are going to deploy prefixes, assign customer gateways and how we are going to number our own infrastructure in a meaningful way. Although I think Stateless Autoconfiguration will be used quite a deal for nodes that are "clients", most of my customers have large server farms and our infrastructure, of course, has many routers. I would think it would be preferable to be able to either use a DHCPV6 pool or to use manual configuration so that the resulting Interface Identifier is either bounded within a known range (tighter than 64 bits wide) or is a specific predictable address (like ::ABC/128 for all customer Gateways, etc.) or to have patterns like :AAAA: within an Identifier for all Edge Routers for easier "on sight" identification by SysAdmins...

However, after many days of reading, I cannot find any place that specifically details the method one would use to identify suitable ranges to choose from for a manually configured Interface ID or a pool of such IDs. Is it as simple as setting the 71st and 72nd bit and avoiding Anycast addresses?

RFC 5453 seems to be written to address this, but seems to have all the relevant detail missing...

What am I missing? Isn't this a concern for everyone?

[cid:image001.gif [at] 01CBA02D]
chad kissinger | founder-vp | onramp access, llc
p: 512.322.9200 | f: 512.476.2878 | www.onr.com<http://www.onr.com/>
your internet operations | built | deployed | managed

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dr at cluenet

Dec 20, 2010, 9:11 AM

Post #2 of 7 (1271 views)
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Re: Manual Configuration of Interface ID [In reply to]

On Mon, Dec 20, 2010 at 10:05:58AM -0600, Chad Kissinger wrote:
> However, after many days of reading, I cannot find any place that
> specifically details the method one would use to identify suitable
> ranges to choose from for a manually configured Interface ID or a
> pool of such IDs. Is it as simple as setting the 71st and 72nd
> bit and avoiding Anycast addresses?

Those two bits have to be UNSET for non-globally-unique unicast
address (IPv6 host part uses Modified EUI-64, which differs from
standard EUI-64 in having the U/L bit inverted to make locally made-up
"vanity" addresses better readable because compressible).

Best regards,
Daniel

--
CLUE-RIPE -- Jabber: dr [at] cluenet -- dr [at] IRCne -- PGP: 0xA85C8AA0

chad at onr

Dec 20, 2010, 9:27 AM

Post #3 of 7 (1278 views)
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RE: Manual Configuration of Interface ID [In reply to]

So, you are saying that I can choose any 64 bit combination for the Interface ID as long as the 71st and 72nd bits are 0. Right?

chad kissinger | founder-vp | onramp access, llc
p: 512.322.9200 | f: 512.476.2878 | www.onr.com
your internet operations | built | deployed | managed

-----Original Message-----
From: ipv6-ops-bounces+chad=onr.com [at] lists [mailto:ipv6-ops-bounces+chad=onr.com [at] lists] On Behalf Of Daniel Roesen
Sent: Monday, December 20, 2010 11:11 AM
To: ipv6-ops [at] lists
Subject: Re: Manual Configuration of Interface ID

On Mon, Dec 20, 2010 at 10:05:58AM -0600, Chad Kissinger wrote:
> However, after many days of reading, I cannot find any place that
> specifically details the method one would use to identify suitable
> ranges to choose from for a manually configured Interface ID or a
> pool of such IDs. Is it as simple as setting the 71st and 72nd
> bit and avoiding Anycast addresses?

Those two bits have to be UNSET for non-globally-unique unicast
address (IPv6 host part uses Modified EUI-64, which differs from
standard EUI-64 in having the U/L bit inverted to make locally made-up
"vanity" addresses better readable because compressible).

Best regards,
Daniel

--
CLUE-RIPE -- Jabber: dr [at] cluenet -- dr [at] IRCne -- PGP: 0xA85C8AA0

dr at cluenet

Dec 20, 2010, 9:39 AM

Post #4 of 7 (1278 views)
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Re: Manual Configuration of Interface ID [In reply to]

On Mon, Dec 20, 2010 at 11:27:53AM -0600, Chad Kissinger wrote:
> So, you are saying that I can choose any 64 bit combination for the
> Interface ID as long as the 71st and 72nd bits are 0. Right?

Except anycast, yes. I'm not aware of further limitations or
considerations, but this mailing list has more than 1000 subscribers,
let's wait for further input. :-)

Best regards,
Daniel

--
CLUE-RIPE -- Jabber: dr [at] cluenet -- dr [at] IRCne -- PGP: 0xA85C8AA0

chad at onr

Dec 20, 2010, 1:50 PM

Post #5 of 7 (1273 views)
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RE: Manual Configuration of Interface ID [In reply to]

Well, no other input yet, but through RFC 5375, I have compiled the following:

In manually choosing a 64 bit IPV6 Interface ID, you should follow the following rules (stated in terms of hexadecimal choices):

1. Do not use all 0s. (interferes with Router Anycast)
2. Do not use all 0s with one character at the end (interferes with Embedded-RP RFC 3956)
3. Do not use all Fs followed by 80 through FF I.e. do not use FFFF:FFFF:FFFF:FF80 through FFFF:FFFF:FFFF:FFFF (interferes with Anycast)
4. Do not use something that begins with 0000:5EFE (interferes with ISATAP RFC5214)
5. The second hexadecimal character of the 64 bit Interface ID must be 0, 4, 8 or C i.e. X8XX:XXXX:XXXX:XXXX where the 8 can be replaced with 0, 4 or C (71st and 72nd bit set to 0)

Any other input? Corrections?

chad kissinger | founder-vp | onramp access, llc
p: 512.322.9200 | f: 512.476.2878 | www.onr.com
your internet operations | built | deployed | managed

-----Original Message-----
From: ipv6-ops-bounces+chad=onr.com [at] lists [mailto:ipv6-ops-bounces+chad=onr.com [at] lists] On Behalf Of Daniel Roesen
Sent: Monday, December 20, 2010 11:39 AM
To: ipv6-ops [at] lists
Subject: Re: Manual Configuration of Interface ID

On Mon, Dec 20, 2010 at 11:27:53AM -0600, Chad Kissinger wrote:
> So, you are saying that I can choose any 64 bit combination for the
> Interface ID as long as the 71st and 72nd bits are 0. Right?

Except anycast, yes. I'm not aware of further limitations or
considerations, but this mailing list has more than 1000 subscribers,
let's wait for further input. :-)

Best regards,
Daniel

--
CLUE-RIPE -- Jabber: dr [at] cluenet -- dr [at] IRCne -- PGP: 0xA85C8AA0

pekkas at netcore

Dec 20, 2010, 10:19 PM

Post #6 of 7 (1260 views)
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RE: Manual Configuration of Interface ID [In reply to]

On Mon, 20 Dec 2010, Chad Kissinger wrote:
> In manually choosing a 64 bit IPV6 Interface ID, you should follow the following rules (stated in terms of hexadecimal choices):
>
...
> 2. Do not use all 0s with one character at the end (interferes with Embedded-RP RFC 3956)

Use for what?

If you do use multicast, it's true that you may want to use some
chracters for RFC 3956 purposes. But given that you can also vary
this by picking a different prefix length (e.g. a new /48), for a
typical ISP this is not really a problem. So there is no inherent
problem with using addresses above for non-multicast-RP purposes, you
can just pick something else if you need to.

--
Pekka Savola "You each name yourselves king, yet the
Netcore Oy kingdom bleeds."
Systems. Networks. Security. -- George R.R. Martin: A Clash of Kings

brian.e.carpenter at gmail

Apr 12, 2011, 12:32 AM

Post #7 of 7 (899 views)
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Re: Manual Configuration of Interface ID [In reply to]

On 2011-04-12 06:41, Jim Kirby wrote:

> The use of u/g bits came after discussions about the 8+8/GSE proposals. I don't know if the more modern versions (ILNP) depend on this property or not. In any case for _existing_ implementations the setting of those bits does not matter. There are no implementations that interpret the interface-ids.

That's irrelevant. The address standard *requires* the u/g bits to be set
appropriately. Until that changes, we have to do so.

(I believe that ILNP doesn't care, but that's not the point.)

Brian

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