Re: Since you are in a teaching mode... [7:42913]
It has to catch on doesn't it?
Do we have a choice? I mean we are nearing half utilization of ipv4 space.
(granted a lot is being wasted through various misconfigured networks or
address space that is no longer needed)
But honestly... What happens when every person in the world has 2-3 ip
addresses for themselves? My isp will hand me one for my home network. My
cell phone carrier will assign me one so I can stay connected when I am
away. My SUV certainly needs one...I mean how else I am to send email in an
efficient manner from my laptop? How on earth are my kinds going to be able
to play quake on long road trips? On that note, will my laptop have a
wireless nic in it? Well it seemingly would have to in order for me to
maximize my own personal utilization.
In that respect, ipv4 is already dead. Is it not? What other choices are
there? Unless every service we subscribe to is based on PAT, we're
screwed... heaven forbid I'm ssh'd int my network via my phone/pda and the
translation table gets cleared!.. BOY will I be upset!
:)
-Patrick
>>> "Priscilla Oppenheimer" 04/30/02 09:21PM >>>
At 04:45 PM 4/30/02, Michael L. Williams wrote:
>I'm sure I'm missing something and I need to read and learn more about IPv6
>(when's your book coming out? =)...
July. The publisher is slow. The book won't cover IPv6 in detail though.
Although it might seem like I'm a big proponent of it, I'm not really sure
it will catch on.
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Re: Since you are in a teaching mode... [7:42913]
Let me make some general comments. I think people are missing some
of the fundamental architectural concepts of IPv6. Indeed, I was one
of the people in the final vote (well, consensus) at the Toronto IETF
where we decided on 128 versus 64 bits.
It is NOT the intention of IPv6 to expand the address space so that
everyone can have their own static address. Addresses have two
distinct functions that coexist in IPv4, but that IPv6, not
completely cleanly, tries to separate.
These functions are location and identification. Location is
routing-oriented and tells you how to get somewhere. Identification
identifies a specific host or interface. In very general terms, the
high-order 64 bits of a v6 address are used mostly for location, to
reach a particular scope called a "site." The next 64 bits identify
(potentially with levels of aggregation), hosts within that site.
Again simplifying greatly, renumbering to a new carrier requires you
to change the locator but not the identifier. Moving a host within a
scope may require you to change the identifier but not the locator.
There are some forms of multihoming that aren't completely solved,
and the multi6 Working Group is trying to come up with strateies.
The high-order locator part has at least three levels of aggregation
for public addressing: Top-Level Aggregator, Second-Level
Aggregator, and Next-Level Aggregator.
At 11:25 PM -0400 4/30/02, Michael L. Williams wrote:
>Comments inline
>
>"Priscilla Oppenheimer" wrote in message
>[EMAIL PROTECTED]">news:[EMAIL PROTECTED]...
>> > however, it seems in an attempt to make
>> >addressing a convenience (where it doesn't take skill to understand and
>do
>> >it), there will be wasted space..
Absolutely, positively, the architects intended to waste some space
to avoid some of the convolutions we go through with V4.
> >
>> So? 128 bits is a lot of bits. In fact, there's more waste than you may
>> realize. In a number of the formats, Interface IDs are required to be 64
>> bits long and to be constructed in IEEE EUI-64 format. EUI-64 based
>> Interface identifiers may have global scope when a global token is
>> available (e.g., IEEE 48-bit MAC) or may have local scope where a global
>> token is not available (e.g., serial links, tunnel end-points, etc.)
>
>So? Isn't it dangerous to approach a new technology (128-bit addressing
>scheme) with such a "ah, who cares if we waste there's so much"
>attitude? I realize 128 bits is alot of bits now. but I also remember
>when 640K was alot of memory ("no one will ever need more than 640K")
There was some fairly extensive analysis done to suggest that we have
to get considerably off the planet before 128 bits turns out not to
be enough. I can't cite the specific RFCs, but they are among the V6
documents. Also look for a couple of RFCs that talk about the "H
ratio" for address space.
> I
>remember when 32-bits of address space (IPv4) was considered endless, so why
>bother conserving address space, etc. and now look at where we are
>Now we have to use NAT at every turn to "reuse" 10.x.x.x and 192,168.x.x on
>private and corporate LANs because "real" IPs are so scarce. Now ISPs give
>you the 3rd degree, mounds of paperwork, and many times request usage
>details for you to justfy that /26 they allocated to you These problems
>could have been avoided with IPv4 with better address management and
>allocation ( I mean, MIT and IBM both have their own /8s... neither
>organization could dream of using all 16.7 million of those addresses
>that equals major waste)... but again, that was back when "32-bits was alot
>of bits". so we shouldn't view 128-bits as a lot of bits for that
>matter, IMHO, we should treat every new address as a precious commodity as
>we do IPv4 addresses now..
>
>> Regarding IPv6 autoconfiguration addresses, I'm no expert. You'll want to
>> read the RFCs to answer those questions. But I think your fears about
> > summarization are unfounded. RFC 2723 says this: "IPv6 unicast addresses
>> are aggregatable with contiguous bit-wise masks similar to IPv4 addresses
>> under Class-less Interdomain Routing [CIDR]."
>
>So that RFC2723 is saying is that IPv6 has the ability to be aggregatable
>like IPv4 under CIDR. Great... but ability to be aggregated means nothing
>if the addresses are discontiguously allocated (i.e. are allocated in a
>manner that isn't condusive to aggregation), as is the case with IPv4
>currently.
You may be missing that the high-order (itself subdivided) and
low-order parts are assigned separately. One can change without
affecting the other, in most cases.
>If IPv4 addresses were allocated properly, BGP routing tables
>would be 4MB, not 128MB.
No, probably not, because we see the trend that users want to
multihome in a manner that simply is not conducive to aggregation.
Other schemes are being discussed, such as scoping the propagation of
anno
Re: Since you are in a teaching mode... [7:42913]
Comments inline
"Priscilla Oppenheimer" wrote in message
[EMAIL PROTECTED]">news:[EMAIL PROTECTED]...
> > however, it seems in an attempt to make
> >addressing a convenience (where it doesn't take skill to understand and
do
> >it), there will be wasted space..
>
> So? 128 bits is a lot of bits. In fact, there's more waste than you may
> realize. In a number of the formats, Interface IDs are required to be 64
> bits long and to be constructed in IEEE EUI-64 format. EUI-64 based
> Interface identifiers may have global scope when a global token is
> available (e.g., IEEE 48-bit MAC) or may have local scope where a global
> token is not available (e.g., serial links, tunnel end-points, etc.)
So? Isn't it dangerous to approach a new technology (128-bit addressing
scheme) with such a "ah, who cares if we waste there's so much"
attitude? I realize 128 bits is alot of bits now. but I also remember
when 640K was alot of memory ("no one will ever need more than 640K") I
remember when 32-bits of address space (IPv4) was considered endless, so why
bother conserving address space, etc. and now look at where we are
Now we have to use NAT at every turn to "reuse" 10.x.x.x and 192,168.x.x on
private and corporate LANs because "real" IPs are so scarce. Now ISPs give
you the 3rd degree, mounds of paperwork, and many times request usage
details for you to justfy that /26 they allocated to you These problems
could have been avoided with IPv4 with better address management and
allocation ( I mean, MIT and IBM both have their own /8s... neither
organization could dream of using all 16.7 million of those addresses
that equals major waste)... but again, that was back when "32-bits was alot
of bits". so we shouldn't view 128-bits as a lot of bits for that
matter, IMHO, we should treat every new address as a precious commodity as
we do IPv4 addresses now..
> Regarding IPv6 autoconfiguration addresses, I'm no expert. You'll want to
> read the RFCs to answer those questions. But I think your fears about
> summarization are unfounded. RFC 2723 says this: "IPv6 unicast addresses
> are aggregatable with contiguous bit-wise masks similar to IPv4 addresses
> under Class-less Interdomain Routing [CIDR]."
So that RFC2723 is saying is that IPv6 has the ability to be aggregatable
like IPv4 under CIDR. Great... but ability to be aggregated means nothing
if the addresses are discontiguously allocated (i.e. are allocated in a
manner that isn't condusive to aggregation), as is the case with IPv4
currently. If IPv4 addresses were allocated properly, BGP routing tables
would be 4MB, not 128MB. I know you understand allocating addresses in a
manner that makes summarization possible, and you know there are ways to
assign addresses (poorly) that keeps an adminstrator from being able to
summarize. So even tho IPv4 (and IPv6) support aggregation, if allocated
improperly, the aggregation "feature" vanishes..that's all I was saying
> >The only people that want
> >"auto-addressing", IMHO, want it out of laziness...
>
> People don't want autoconfiguration because of laziness. They want it
> because sometimes there's no network administrator available and maybe
> there never was one available (to set up a server, for example). Take the
> typical kitchen, laundry room (your washing machine may have a L3 address
> some day), car, space station, hotel lobby, Starbucks, park, real-estate
> office, many other small offices, etc.
Point well taken. My comment about laziness was off target. As you
mention, in the future cars, toasters, washing machines, etc will be using
IP and so there needs to be a good methods for these devices to obtain an
IP. (perhaps they could just be embedded like MACs are)...
> You made fun of AppleTalk, but there is an IETF movement afoot to
> standardize user-friendliness, autoconfiguration, and many other AppleTalk
> themes. See the work of the Zero Configuration Networking working group
here:
Hey! I wasn't making fun of AppleTalk. just pointing out things I
thought were lame =) I can't really explain it... it's just a nagging
feeling. oh... that's just my dog pulling on my pants leg =)
But, it seems to me that, even on Macs, if AppleTalk were that easy to
setup/use and administer, then why has TCP/IP pretty much crushed it (along
with IPX, etc)? I guess my point is, ease of configuration and user
friendliness, although niceties, will always take a back seat to core
functionality and compatibility. And any sort of autoconfiguration isn't
worth the price if it autoconfigures at the expense of proper address
allocation.
Also keep in mind that the Zero Configuration Networking, no matter how well
thought out or planned, will be just like any other "Zero" anything (i.e.
Zero Effort Networking (Z.E.N. Works) ala Novell) and will be anything but
Zero configuration/effort, etc... =)
Mike W.
*** All comments above a
Re: Since you are in a teaching mode... [7:42913]
At 04:45 PM 4/30/02, Michael L. Williams wrote: >I'm sure I'm missing something and I need to read and learn more about IPv6 >(when's your book coming out? =)... July. The publisher is slow. The book won't cover IPv6 in detail though. Although it might seem like I'm a big proponent of it, I'm not really sure it will catch on. > however, it seems in an attempt to make >addressing a convenience (where it doesn't take skill to understand and do >it), there will be wasted space.. So? 128 bits is a lot of bits. In fact, there's more waste than you may realize. In a number of the formats, Interface IDs are required to be 64 bits long and to be constructed in IEEE EUI-64 format. EUI-64 based Interface identifiers may have global scope when a global token is available (e.g., IEEE 48-bit MAC) or may have local scope where a global token is not available (e.g., serial links, tunnel end-points, etc.) Regarding IPv6 autoconfiguration addresses, I'm no expert. You'll want to read the RFCs to answer those questions. But I think your fears about summarization are unfounded. RFC 2723 says this: "IPv6 unicast addresses are aggregatable with contiguous bit-wise masks similar to IPv4 addresses under Class-less Interdomain Routing [CIDR]." >The only people that want >"auto-addressing", IMHO, want it out of laziness... People don't want autoconfiguration because of laziness. They want it because sometimes there's no network administrator available and maybe there never was one available (to set up a server, for example). Take the typical kitchen, laundry room (your washing machine may have a L3 address some day), car, space station, hotel lobby, Starbucks, park, real-estate office, many other small offices, etc. You made fun of AppleTalk, but there is an IETF movement afoot to standardize user-friendliness, autoconfiguration, and many other AppleTalk themes. See the work of the Zero Configuration Networking working group here: http://www.ietf.org/html.charters/zeroconf-charter.html Priscilla > I mean, technologies >like DHCP can handle dynamic assignment of addrs from a given scope, so why >concentrate on fixing something that's not broken. Why bother wasting time >with "convenience" of auto-addressing and just fix what's wrong with our >system now (i.e. it's 32-bit which the 128-bit will fix, and the fact that >IPs weren't handed out in a way that was condusive to summarization, which >can be fixed when they start handing out IPv6 addrs) > >Mike W. Priscilla Oppenheimer http://www.priscilla.com Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=42934&t=42913 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: Since you are in a teaching mode... [7:42913]
An IPv6 address may be shortened by leaving off the leading zeros in the address, but this can only be done once in the address. An example would be the address of 12AB:::CD30::::/64 could be shortened to 12AB::CD30::::/64 or 12AB:::CD30::/64 Check out RFC 2373 for more info on IPv6 Original Message Follows From: "Priscilla Oppenheimer" Reply-To: "Priscilla Oppenheimer" To: [EMAIL PROTECTED] Subject: Re: Since you are in a teaching mode... [7:42913] Date: Tue, 30 Apr 2002 16:15:59 -0400 At 03:22 PM 4/30/02, Chris Charlebois wrote: >How is that different than IPX? It seems if you are going to increase the >size of the address enough to include the MAC address, assigning a unique >(whether locally or globally) become trivial. After all, MAC addresses are, >in thoery, globally unique. Then the only question is routability, which >means network information picked up from the line (as in IPX) or from a >server (in IPv6 as you seem to indicate in your post). IPv6 stateless autoconfiguration is similar to IPX addressing, although your last statement is sort of backwards. No server is required in IPv6. The client can listen to Router Advertisements that provide a prefix. (A host can also force an immediate Router Advertisement by transmitting a Router Solicitation message to the all-routers multicast address.) With IPX, a client broadcasts a Find Network Number. A server or router must respond. >My greatest concern about IPv6 (and this is probably due to my ignorance on >the subject) is the apperent reliance on name resolution. I just think how >oftern in my line of work it is easiest and most expedicious to use the IP >address rather than the name. That isn't going to be feasible when the >address is 60 odd characters long. Am I missing something, or are the days >of 'no ip domain-lookup' soon to be a thing of the past? There are shorthand ways of specifying IPv6 addresses I think. Maybe someone else knows for sure. Priscilla Priscilla Oppenheimer http://www.priscilla.com _ Chat with friends online, try MSN Messenger: http://messenger.msn.com Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=42928&t=42913 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: Since you are in a teaching mode... [7:42913]
Also.. (I need to re-read your post to get a better understanding of the mechanism in IPv6)... how will self-allocating addresses affect summarization.. part of what's killing BGP/internet routers is that addresses are scattered around and makes the table much larger than what it should be. If the lower order bits were based on MAC addr, it seems that there would be a huge waste of address space.. i.e. if the MAC addr of a NIC is used as the last (least significant to everyone but IBM) 48 bits, wouldn't that mean the smallest scope would contain 2^48 addresses (i.e. the first 80 bits are "assigned" and the last 48 are MAC based) which is 65536 times more than all IPv4 IP space combined. So when Joe Blow opens a couple of furniture store and puts 5 PCs in, he'll have 2^48 addresses assigned because that's the smallest scope? I'm way off in speculation land at this point. so feel free to publicly humiliate me to set the record straight =) I'm sure I'm missing something and I need to read and learn more about IPv6 (when's your book coming out? =)... however, it seems in an attempt to make addressing a convenience (where it doesn't take skill to understand and do it), there will be wasted space.. The only people that want "auto-addressing", IMHO, want it out of laziness... I mean, technologies like DHCP can handle dynamic assignment of addrs from a given scope, so why concentrate on fixing something that's not broken. Why bother wasting time with "convenience" of auto-addressing and just fix what's wrong with our system now (i.e. it's 32-bit which the 128-bit will fix, and the fact that IPs weren't handed out in a way that was condusive to summarization, which can be fixed when they start handing out IPv6 addrs) Mike W. Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=42925&t=42913 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: Since you are in a teaching mode... [7:42913]
At 03:22 PM 4/30/02, Chris Charlebois wrote: >How is that different than IPX? It seems if you are going to increase the >size of the address enough to include the MAC address, assigning a unique >(whether locally or globally) become trivial. After all, MAC addresses are, >in thoery, globally unique. Then the only question is routability, which >means network information picked up from the line (as in IPX) or from a >server (in IPv6 as you seem to indicate in your post). IPv6 stateless autoconfiguration is similar to IPX addressing, although your last statement is sort of backwards. No server is required in IPv6. The client can listen to Router Advertisements that provide a prefix. (A host can also force an immediate Router Advertisement by transmitting a Router Solicitation message to the all-routers multicast address.) With IPX, a client broadcasts a Find Network Number. A server or router must respond. >My greatest concern about IPv6 (and this is probably due to my ignorance on >the subject) is the apperent reliance on name resolution. I just think how >oftern in my line of work it is easiest and most expedicious to use the IP >address rather than the name. That isn't going to be feasible when the >address is 60 odd characters long. Am I missing something, or are the days >of 'no ip domain-lookup' soon to be a thing of the past? There are shorthand ways of specifying IPv6 addresses I think. Maybe someone else knows for sure. Priscilla Priscilla Oppenheimer http://www.priscilla.com Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=42923&t=42913 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Since you are in a teaching mode... [7:42913]
How is that different than IPX? It seems if you are going to increase the size of the address enough to include the MAC address, assigning a unique (whether locally or globally) become trivial. After all, MAC addresses are, in thoery, globally unique. Then the only question is routability, which means network information picked up from the line (as in IPX) or from a server (in IPv6 as you seem to indicate in your post). My greatest concern about IPv6 (and this is probably due to my ignorance on the subject) is the apperent reliance on name resolution. I just think how oftern in my line of work it is easiest and most expedicious to use the IP address rather than the name. That isn't going to be feasible when the address is 60 odd characters long. Am I missing something, or are the days of 'no ip domain-lookup' soon to be a thing of the past? Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=42918&t=42913 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
