IPv6 woes - RFC

Victor Kuarsingh victor at jvknet.com
Wed Sep 29 16:24:46 UTC 2021


On Wed, Sep 29, 2021 at 10:55 AM Owen DeLong via NANOG <nanog at nanog.org>
wrote:

> Use SLAAC, allocate prefixes from both providers. If you are using
> multiple routers, set the priority of the preferred router to high in the
> RAs. If you’re using one router, set the preferred prefix as desired in the
> RAs.
>
> Owen
>

I agree this works, but I assume that we would not consider this a consumer
level solution (requires an administrator to make it work).  It also
assumes the local network policy allows for auto-addressing vs. requirement
for DHCP.

I have had IPv6 in my home for a long time now using multiple providers,
but it definitely works with high touch admin.  I don't see this as a
barrier to deploy IPv6 though (don't read that into my response).  But IPv6
still has a few corner cases that require some TLC.

regards,

Victor K






>
>
> On Sep 29, 2021, at 07:35, Christopher Morrow <morrowc.lists at gmail.com>
> wrote:
>
> 
>
>
> On Wed, Sep 29, 2021 at 4:39 AM <borg at uu3.net> wrote:
>
>> Oh well.. Then how you gonna solve the el-cheapo SOHO multihoming?
>>
>> Im currently dual homed, having 2 uplinks, RFC1918 LAN, doing policy
>> routing and NATing however I want..
>>
>>
> why of COURSE you do source address selection!
> so simple!
>
>
>>
>> ---------- Original message ----------
>>
>> From: Mark Andrews <marka at isc.org>
>> To: borg at uu3.net
>> Cc: nanog at nanog.org
>> Subject: Re: IPv6 woes - RFC
>> Date: Wed, 29 Sep 2021 00:28:40 +1000
>>
>>
>>
>> > On 28 Sep 2021, at 19:19, borg at uu3.net wrote:
>> >
>> > Heh, NAT is not that evil after all. Do you expect that all the home
>> > people will get routable public IPs for all they toys inside house?
>>
>> Yes! Remember routable does not mean that it is reachable from outside.
>>
>> > And if they change ISP they will get new range?
>>
>> Yes!  What do you think DHCPv6 Prefix Delegation is all about?  It
>> has only been specified for 18 years now.  The IPv6 address ranges ISP
>> get for RIRs are based on handing out multiple /64 to every customer.
>>
>> > Doesnt sounds nice to me.. But I guess I its just me
>>
>> It sounds like you need to do some reading about IPv6, then actually
>> use it.  100s of millions of home customers are get routable IPv6 prefixes
>> today around the world.  It's not scary.  Things don˙˙t blow up.
>>
>> > Yeah I am aware of putting additional aliases on loopback.
>> >
>> > No futher comment about ND and DHCP.
>> >
>> > Well, at a time when TCP/IP was invented, 32bit address space looked
>> > pretty much big... I dont blame them than they didnt predicted future..
>> > Unfortunately, cant say the same about IPv6 R&D taskforce ;)
>> >
>> > Hah, multicast... Ill skip it.
>> >
>> > Followed change to support CIDR, Internet was still small and considered
>> > R&D field...
>> >
>> > Okey, I think its no need to futher pollute NANOG list with this.
>> > I said at the begining that this is just my subjective opinion.
>> > This will not help IPv6 case at all.
>> >
>> > At least from my (2) standpoint it would be really cool that IPv6
>> > would be finally addopted.
>> >
>> > I just wanted to share my toughts about why im not big fan of IPv6.
>> > I also wanted to hear other opinions what they dislike about it, no
>> > list of how cool IPv6 is and how everyone should use it right away.
>> >
>> >
>> > ---------- Original message ----------
>> >
>> > From: Owen DeLong <owen at delong.com>
>> > To: borg at uu3.net
>> > Cc: nanog at nanog.org
>> > Subject: Re: IPv6 woes - RFC
>> > Date: Sat, 25 Sep 2021 12:01:22 -0700
>> >
>> >
>> >
>> >> On Sep 25, 2021, at 01:57 , borg at uu3.net wrote:
>> >>
>> >> Well, I think we should not compare IPX to IPv4 because those protocols
>> >> were made to handle completly different networks?
>> >>
>> >> Yeah, IPv6 is new, but its more like revolution instead of evolution.
>> >>
>> >> Well, Industry seems to addapt things quickly when they are good
>> enough.
>> >> Better things replace worse. Of course its not always the case,
>> sometimes
>> >> things are being forced here.. And thats how I feel about IPv6..
>> >
>> > Sometimes worse things replace better. NAT, for example was definitely
>> not
>> > an improvement to IPv4. It was a necessary evil intended to be a
>> temporary
>> > fix.
>> >
>> >>
>> >> IPv4 Lookback is 127.0.0.1/8
>> >> You can use bind IPs within range by applications. Handy
>> >> In IPv6 its not the case.
>> >
>> > You are free to assign any additional IPv6 addresses you like to the
>> loopback
>> > interface and then bind them to applications. Personally, I haven˙˙t
>> found a
>> > particularly good use for this, but it is possible.
>> >
>> > It does mean that instead of wasting 1/256th of the entire address space
>> > in every context on loopbacks, you have to assign what you need there,
>> > but you can easily assign a /64 prefix to a loopback interface and have
>> > applications bind within range.
>> >
>> >> IPv6 ND brings new problems that has been (painfully?) fixed in IPv4.
>> >> Tables overflows, attacks and DDoS.. Why to repeat history again?
>> >
>> > Table overflows weren˙˙t fixed in IPv4 and have nothing to do with ND
>> vs.
>> > ARP. Table overflows are (not really an issue in my experience) the
>> > result of a larger address space than the memory available for the L2
>> > forwarding table on switches or the ND table on hosts. This isn˙˙t due
>> > to a difference in ND vs. ARP. It is due to the fact that there are no
>> > 64-bit networks in IPv4, but they are commonplace in IPv6.
>> >
>> > Mostly this has been solved in software by managing table discards more
>> > effectively.
>> >
>> >> IPv6 DHCP: Im not using IPv6, but I heard ppl talking about some
>> >> issues. If this is not the case, im sorry. Its been a while when I
>> last time
>> >> played with IPv6...
>> >
>> > I am using IPv6 and I˙˙m using IPv6 DHCP. I haven˙˙t encountered any
>> significant
>> > problems with it other than some minor inconveniences introduced by the
>> ability
>> > to have different DUID types and vendors doing semi-obnoxious things
>> along that
>> > line.
>> >
>> >> IPv6 interop: yeah, I agree here.. But people involved with IPv6
>> should
>> >> think about some external IPv4 interop.. Internet was exploding at
>> 1997..
>> >> Maybe they had hope that everyone upgrade like in CIDR case. And maybe
>> it
>> >> could happen if IPv6 wasnt so alien ;)
>> >
>> > It was thought about˙˙ It was considered. It was long pondered. Problem
>> was,
>> > nobody could come up with a way to overcome the fact that you can˙˙t put
>> > 128 bits of data in a 32 bit field without loss.
>> >
>> > IPv6 really isn˙˙t so alien, so I don˙˙t buy that argument. The
>> software changes
>> > necessary to implement IPv6 were significantly bigger than CIDR and IPv6
>> > affected applications, not just network. There was no way around these
>> > two facts. The IPv6 network stack did get adopted and implemented nearly
>> > as fast as CIDR and virtually every OS, Switch, Router has had IPv6
>> support
>> > for quite some time now at the network stack level. It is applications
>> and
>> > content providers that are lagging and they never did anything for CIDR.
>> >
>> >> As for IPv4 vs IPv6 complexity, again, why repeat history.
>> >
>> > What complexity?
>> >
>> >> Biggest IPv4
>> >> mistake was IPv4 being classfull. It was fixed by bringing CIDR into
>> game.
>> >
>> > No, biggest IPv4 mistake was 32-bit addresses. A larger address would
>> have been
>> > inconvenient in hardware at the time, but it would have made IPv4 much
>> more
>> > scalable and would have allowed it to last significantly longer.
>> >
>> >> (Another big mistake was class E reservation...)
>> >
>> > Not really. It was a decision that made sense at the time. Class D
>> reservation
>> > made sense originally too. Without it, we wouldn˙˙t have had addresses
>> available
>> > to experiment with or develop multicast.
>> >
>> > There was no way to know at the time that decision was made that IPv4
>> would run
>> > out of addresses before it would find some new thing to experiment with.
>> >
>> >> Internet was tiny at that time so everyone followed.
>> >
>> > Followed what, exactly?
>> >
>> >> Image something like this today? Same about IPv6.. it brings
>> >> forced network::endpoint probably due to IoT, sacrificing flexibility.
>> >
>> > I can˙˙t parse this into a meaningful comment. Can you clarify please?
>> > What is ˙˙forced network::endpoint˙˙ supposed to mean and what does it
>> > have to do with IoT? What flexibility has been sacrificed?
>> >
>> >> Again, I dont want to really defend my standpoint here. Its too late
>> for
>> >> that. I kinda regret now dropping into discussion...
>> >
>> > OK, so you want to make random comments which are not even necessarily
>> > true and then walk away from the discussion? I have trouble
>> understanding
>> > that perspective.
>> >
>> > I˙˙m not trying to bash your position or you. I˙˙m trying to understand
>> your
>> > objections, figure out which ones are legitimate criticism of IPv6,
>> which
>> > ones are legitimate criticism, but not actually IPv6, and which ones
>> > are simply factually incorrect. For the last category, I presume that
>> comes
>> > from your lack of actual IPv6 experience or some other form of ignorance
>> > and I˙˙d like to attempt useful education to address those.
>> >
>> > Owen
>> >
>> >>
>> >>
>> >> ---------- Original message ----------
>> >>
>> >> From: Grant Taylor via NANOG <nanog at nanog.org>
>> >> To: nanog at nanog.org
>> >> Subject: Re: IPv6 woes - RFC
>> >> Date: Fri, 24 Sep 2021 14:26:27 -0600
>> >>
>> >> On 9/24/21 11:53 AM, borg at uu3.net wrote:
>> >>> Well, I see IPv6 as double failure really.
>> >>
>> >> I still feel like you are combining / conflating two distinct issues
>> into one
>> >> generalization.
>> >>
>> >>> First, IPv6 itself is too different from IPv4.
>> >>
>> >> Is it?  Is it really?  Is the delta between IPv4 and IPv6 greater than
>> the delta
>> >> between IPv4 and IPX?
>> >>
>> >> If anything, I think the delta between IPv4 and IPv6 is too small.
>> Small enough
>> >> that both IPv4 and IPv6 get treated as one protocol and thus a lot of
>> friction
>> >> between the multiple personalities therein.  I also think that the
>> grouping of
>> >> IPv4 and IPv6 as one protocol is part of the downfall.
>> >>
>> >> More over if you think of IPv4 and IPv6 dual stack as analogous to the
>> >> multi-protocol networks of the '90s, and treat them as disparate
>> protocols that
>> >> serve similar purposes in (completely) different ways, a lot of the
>> friction
>> >> seems to make sense and as such becomes less friction through
>> understanding and
>> >> having reasonable expectations for the disparate protocols.
>> >>
>> >>> What Internet wanted is IPv4+ (aka IPv4 with bigger address space,
>> likely
>> >>> 64bit). Of course we could not extend IPv4, so having new protocol is
>> fine.
>> >>
>> >> I don't think you truly mean that having a new protocol is fine.
>> Because if you
>> >> did, I think you would treat IPv6 as a completely different protocol
>> from IPv4.
>> >> E.g. AppleTalk vs DECnet.  After all, we effectively do have a new
>> protocol;
>> >> IPv6.
>> >>
>> >> IPv6 is as similar to IPv4 as Windows 2000 is similar to Windows 98.
>> Or
>> >> "different" in place of "similar".
>> >>
>> >>> It should just fix problem (do we have other problems I am not aware
>> of with
>> >>> IPv4?) of address space and thats it.  Im happy with IPv4, after 30+
>> years of
>> >>> usage we pretty much fixed all problems we had.
>> >>
>> >> I disagree.
>> >>
>> >>> The second failure is adoption. Even if my IPv6 hate is not rational,
>> adoption
>> >>> of IPv6 is crap. If adoption would be much better, more IPv4 could be
>> used for
>> >>> legacy networks ;) So stuborn guys like me could be happy too ;)
>> >>
>> >> I blame the industry, not the IPv6 protocol, for the lackluster
>> adoption of
>> >> IPv6.
>> >>
>> >>> As for details, that list is just my dream IPv6 protocol ;)
>> >>>
>> >>> But lets talk about details:
>> >>> - Loopback on IPv6 is ::1/128
>> >>>  I have setups where I need more addresses there that are local only.
>> >>>  Yeah I know, we can put extra aliases on interfaces etc.. but its
>> extra
>> >>>  work and not w/o problems
>> >>
>> >> How does IPv6 differ from IPv4 in this context?
>> >>
>> >>> - IPv6 Link Local is forced.
>> >>>  I mean, its always on interface, nevermind you assign static IP.
>> >>>  LL is still there and gets in the way (OSPFv3... hell yeah)
>> >>
>> >> I agree that IPv6 addresses seem to accumulate on interfaces like IoT
>> devices do
>> >> on a network.  But I don't see a technical problem with this in and of
>> itself.
>> >> --  I can't speak to OSPFv3 issues.
>> >>
>> >>> - ULA space, well.. its like RFC1918 but there are some issues with it
>> >>>  (or at least was? maybe its fixed) like source IP selection on with
>> >>>  multiple addresses.
>> >>
>> >> I consider this to be implementation issues and not a problem with the
>> protocol
>> >> itself.
>> >>
>> >>> - Neighbor Discovery protocol... quite a bit problems it created.
>> >>
>> >> Please elaborate.
>> >>
>> >>>  What was wrong w/ good old ARP? I tought we fixed all those problems
>> >>>  already like ARP poisoning via port security.. etc
>> >>
>> >> The apparent need to ""fix / address / respond to a protocol problem
>> at a lower
>> >> layer seems like a problem to me.
>> >>
>> >>> - NAT is there in IPv6 so no futher comments
>> >>> - DHCP start to get working on IPv6.. but it still pain sometimes
>> >>
>> >> What problems do you have with DHCP for IPv6?  I've been using it for
>> the better
>> >> part of a decade without any known problems.  What pain are you
>> experiencing?
>> >>
>> >>> And biggest problem, interop w/ IPv4 was completly failure.
>> >>
>> >> I agree that the interoperability between IPv4 and IPv6 is the tall
>> pole in the
>> >> tent.  But I also believe that's to be expected when trying to
>> interoperate
>> >> disparate protocols.
>> >>
>> >>> From ground zero, I would expect that disparate protocols can't
>> interoperate
>> >> without external support, some of which requires explicit
>> configuration.
>> >>
>> >>> Currently we have best Internet to migrate to new protocol. Why?
>> >>
>> >> The primary motivation -- as I understand it -- is the lack of unique
>> IP
>> >> addresses.
>> >>
>> >>> Because how internet become centralized. Eyeball networks just want
>> to reach
>> >>> content. E2E communication is not that much needed. We have games and
>> >>> enhusiast, but those can pay extra for public IPv4. Or get VPN/VPS.
>> >>
>> >> Now you are talking about two classes of Internet connectivity:
>> >>
>> >> 1)  First class participation where an endpoint /is/ /on/ the Internet
>> with a
>> >> globally routed IP.
>> >> 2)  Second class participation where an endpoint /has/ /access/ /to/
>> the
>> >> Internet via a non-globally routed IP.
>> >>
>> >> There may be some merit to multiple classes of Internet connectivity.
>> But I
>> >> think it should be dealt with openly and above board as such.
>> >>
>> >>> And end comment. I do NOT want to start some kind of flame war here.
>> Yeah I
>> >>> know, Im biased toward IPv4.
>> >>
>> >> I don't view honest and good spirited discussion of facts and
>> understanding to
>> >> be a flame war.  In fact, I view such discussions as a good thing.
>> >>
>> >>> If something new popups, I want it better than previous thingie (a
>> lot) and
>> >>> easier or at least same level of complications, but IPv6 just solves
>> one thing
>> >>> and brings a lot of complexity.
>> >> Please elaborate on the complexity that IPv6 brings that IPv4 didn't
>> also bring
>> >> with it in the '90s?
>> >>
>> >> Would the things that you are referring to as IPv6 complexities have
>> been any
>> >> different if we had started with IPv6 instead of IPv4 in the '80s &
>> '90s?
>> >>
>> >> In some ways it seems to me that you are alluding to the legacy code /
>> equipment
>> >> / understanding / configuration / what have you.  This is something
>> that many
>> >> have been dealing with for quite a while.  The mainframe's ability to
>> run code
>> >> from near half a century ago comes to mind.
>> >>
>> >>> The fact is, IPv6 failed.
>> >>
>> >> I concede that IPv6 has faltered.  But I don't believe it's failed.  I
>> don't
>> >> think it's fair to claim that it has.
>> >>
>> >>> There are probably multiple reasons for it.  Do we ever move to IPv6?
>> I dont
>> >>> know.. Do I care for now? Nope, IPv4 works for me for now.
>> >>
>> >> You are entitled to your own opinion as much as I'm entitled to mine.
>> But the
>> >> key thing to keep in mind is that it's /your/ opinion.  The operative
>> word being
>> >> "your" as in "you".  Your views / opinions / experiences are /yours/.
>> What's
>> >> more important is that other people's views / opinions / experiences
>> may be
>> >> different.
>> >>
>> >>
>> >>
>> >> --
>> >> Grant. . . .
>> >> unix || die
>>
>> --
>> Mark Andrews, ISC
>> 1 Seymour St., Dundas Valley, NSW 2117, Australia
>> PHONE: +61 2 9871 4742              INTERNET: marka at isc.org
>>
>
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