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One Less Reason to Adopt IPv6?
Posted by
CmdrTaco
on Mon Sep 17, 2007 10:19 AM
from the adopt-a-puppy-instead dept.
from the adopt-a-puppy-instead dept.
alphadogg writes "For a decade, IPv6 proponents have pushed this upgrade to the Internet's main communications protocol because of its three primary benefits: a gargantuan address space, end-to-end security, and easier network administration through automatic device configuration. Now it turns out that one of these IPv6 benefits — autoconfiguration — may not be such a boon for corporate network managers. A growing number of IPv6 experts say that corporations probably will skip autoconfiguration and instead stick with DHCP, which has been updated to support IPv6."
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But... (Score:5, Funny)
But puppies don't have a "gargantuan address space" or end-to-end security. Trust me, puppies leak all the time.
Re: But... (Score:5, Funny)
Not to mention the fact that sniffing is a constant problem.
Parent
DHCP in an IPV6 world (Score:5, Interesting)
DHCP doesn't give a network admin any more control over a network, either. That's just a silly statement. How does having a server doling out IP addresses make it any easier to control a network? It's not a like a device *must* be set to use DHCP. It's not difficult to figure out what IP address ranges a DHCP server is not doling out and use that, even on IPV4.
Re:DHCP in an IPV6 world (Score:5, Insightful)
The reality of the situation is that stateless autoconfig in IPv6 is one way to get basic networking connectivity setup, DHCP is another. Depending on your situation, the phase of the moon, and any of a number of philosophical viewpoints held by the network admin, stateless autoconfig might or might not get used. *shrug* Even with stateless autoconfig, DHCPv6 might also get used to configure other information that is not handled by stateless autoconfig (DNS servers, NTP servers, any of a huge list of other things).
The important point to remember, though is *2 YEARS*. That's how long we have until the IPv4 address space is fully allocated at the top level. It may take a little longer (months?) before people start really feeling any pain from that at the end-user level. But its the critically important point for people to realize. Can you be ready for IPv6 in 2 years? You need to be. If its gonna take you 2 years to get IPv6 functioning in your network, then you need to start *NOW*.
Parent
Or have I got this wrong (Score:5, Insightful)
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Re: (Score:3, Insightful)
IMHO, this "much smaller task" isn't quite so small anymore. In fact, it's massive.
IPv6 enabled machines talking to "legacy" IPv4 applications / services is a TRIVIAL task compared to the other way around.
Re: (Score:2)
Well, a lot of governments are g
Re:DHCP in an IPV6 world (Score:5, Insightful)
Son, they've been saying that for 15+ years.
Yes, there is a limit. But once IPV4 address space at the "top level" becomes scarce, it will be handled according to the rules of any scarce commodity - it'll become more expensive. That will encourage efficiency, free space from wasteful users, etc. Then we'll get close again, lather rinse repeat, etc. We will eventually hit the point of "full" but it's not like in September 2010 suddenly there will be no more routable IPs for the next system that needs one.
Parent
Re:DHCP in an IPV6 world (Score:5, Informative)
About once a year I investigate the current state of ipv6 support, and every time so far I have found every major operating system (including linux-based ones) to be inadequate to the task of deploying ipv6. The software support is just not there, on both the system and application levels. Sure, I can configure ipv6 interfaces on hosts and even have some of them set up tunnels and talk to each other, but it is entirely impossible for me to configure a non-trivial network without ipv4 support on every host and still expect it to work, so there's no damned point.
NAT is the solution to the address space problem. Get used to it, because ipv6 has spent the last five years failing to become a solution. When we finally run out of ipv4 addresses, we aren't going to switch to ipv6, we're going to switch to using NAT at the ISPs. You won't get an internet-routeable address for anything other than a server, after that happens - regular DSL lines will be allocated an address from one of the private ranges and NATted onto a smaller pool of routeable addresses as they leave the ISPs network.
It's going to come down to a choice between a technology that has spent years going nowhere and a technology that has spent years being used as the solution to the problem. I know which way the ISPs are all going to jump.
Parent
Re: (Score:3, Interesting)
Re: (Score:2)
You don't take access. We grant it to you.
Re: (Score:2)
Good luck figuring that out over a VPN connection.
I can see both sides of this argument pretty easily. Perhaps you have multiple gateways for different reasons but are too dumb to subnet/VLAN. Of course with 802.1X authentication I'm not sure how that would work without DHCP given that an address is assigned dynamically and RADIUS accounting determines when and if they gain access and for how long among other features.
Theoretically it could be done without DHCP although I imagine the software clients wo
Re:DHCP in an IPV6 world (Score:5, Informative)
IPv6 Autoconf resembles bootP or inverse-arp more than it does DHCP. Also, DHCP has steadily developed a bunch of knobs over the years so that (for instance) IP phones can be told about which TFTP server to use - that sort of functionality doesn't exist in v6 autoconf today. Not to say that it never will, but v6 autoconf doesn't currently have anywhere near the capabilities that v4 DHCP does.
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Re:DHCP in an IPV6 world (Score:5, Informative)
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Re:DHCP in an IPV6 world (Score:4, Informative)
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Re:DHCP in an IPV6 world (Score:5, Informative)
DHCP combined with modern network infrastructure allows network administrators complete control over all addressing issues in the network - including preventing non-DHCP hosts from participating in the network (called DHCP snooping) and location-based services ("DHCP option 82"). DHCP is so much more than just a kludge to get an IP address to the host. Scalability of DHCP allows network administrators to append information such as DNS, NTP, TFTP (for IP Telephony/TV) server information and so much more - default gateway, static routes just to name few. All this is pretty much lacking from IPv6 autoconfiguration.
That's why we tend to like DHCP
Marko
CCIE #18427
Parent
Re: (Score:2)
Re:DHCP in an IPV6 world (Score:4, Insightful)
I run DHCP on my home network to setup: DNS, WINS, Gateway, IP Address, NTP (Time), and other services. I also use it to record MAC addresses for security reasons, and to easily grab them so that I can configure static IPs and DNS names for specific systems without having to ask people for their specific MAC (unless they're coming in wireless...then they need to to get access anyway...).
Point is, it gives me an easy way to manage my network. And honestly, I was looking forward to playing around with IPv6 in the same manner on my home network (because I could, and wanted to experiment), but some things just aren't ready for it yet, and the lack of a DHCPv6 server (at the time) to manage the auto-configuring was an issue too.
Additionally, I have played with IPv6 with its auto-config, which at least under Windows 2003 is a joke as it is a half-baked implementation that is just plain broke. Half the time it works, and half the time it doesn't. And when it doesn't, it is seriously borked, and breaks everything else too. (And I was only running a set of 6 systems (4 servers, and 2 clients) in my test network.) It took a lot of time to get systems reconnected when things failed out due to IPv6 addressing not working. Haven't tried it much under Linux yet...but I would still have Windows clients to support, and VPN and other software that would need supported. (Software I don't control the version or support on...work does.)
Any how...DHCPv6 would have made supporting that test network a lot easier, and actually would have kept it functional. I cannot imagine what kind of problems admins will have trying to deploy IPv6 with auto-config on a larger network. (Imagine, your computer gets a new IPv6 address just because you rebooted...not make that your server and you could really screw up your network quickly.)
Parent
Re: (Score:3, Interesting)
Sure it does.
I can set certain classes of my clients to use a certain set of DNS servers; I can black list specific MAC addresses from getting an address, or I can grant them addresses on a VLAN that has no corporate access but has Internet access; I can have a central location that records the addresses of my clients and who they're linked with, etc...
At least these are services I'm used to right now with DHCPv4. I'm going to be
Re:DHCP in an IPV6 world (Score:4, Informative)
Parent
Why did everyone completely ignore ISO? (Score:2)
And look, nobody wants the new wheel anyway.
Meh. Get of my lawn. Go on, the lot of you.
Re: (Score:2, Informative)
I guess it boils down to: because the full ISO stack never worked.
First off, it was never "finished", insofar as many features available in other things were/are not available in OSI.... Given the level of "optional" features of OSI, in practice, full systems never did manage to communicate with each other. Given the complexity of the standards, building software, and debugging things, was very, very hard.
I am more then willing to grant that some very specific bits coming out of the OSI process were good
Re:Why did everyone completely ignore ISO? (Score:5, Interesting)
That's not the problem that I saw, 15 or 20 years back, when I was involved in a number of OSI implementation projects. We were in fact looking at several competing protocols, with the idea of implementing them all and developing test suites to determine their good and bad points.
But something interesting happened on all the OSI projects: We'd need the specs, of course, and you couldn't download them. You had to order the hard copy. This meant going through the usual corporate red tape for ordering stuff. You'd fill out a requirement doc, get it ok'd. You'd fill out a purchase req, figure out whose signatures you needed, and have the secretaries work on collecting the signatures. You'd mail off the order, and wait.
Meanwhile, since there was a lot of waiting to do, we'd work on the IP version. We'd download the RFCs, spend an hour or so reading and a few hourse discussing, and then we'd sit down at a terminal and start coding. We'd be at the testing stage within a day, and have usable results in a few days. By the time the OSI specs showed up on our desks, we'd have had the IP version up and running for weeks. While we were reading the OSI specs (always much larger than the IP specs), we'd have users getting experience with the IP version, and sending in bug reports and/or change/feature requests. By the time we finally got an OSI version to the alpha stage, the IP version would be ready to send to the first customers.
If the OSI gang had had the sense to make their docs available free on the Internet, they might not have lost so badly. But by trying to make the specs a profit center, and by using a different competing delivery network (the postal system), they put a major time blockade in the way of developers. So they lost out big time to IP.
I've never been all that convinced that IP was any better than OSI, especially now with the big migration to IPv6 peering over the horizon. But I never really got a good chance to test them and compare their capabilities. The OSI version of our code was always so far behind the IP version that the whole issue was moot. IP won every race, because OSI was so slow out of the starting box. And that was because we developers couldn't get out hands on the specs in a timely manner.
Parent
Missing DNS (Score:5, Insightful)
1) DNS server information wasn't baked in from the beginning (there are now some drafts to fix this, but I haven't yet seen the working code) - all this time, and we managed to recreate BootP...
2) Because autoconfiguration uses
3) Just try it with VMWare or other virtualization software. Ouch. There's a whole lot of borked there.
4) Obviously you wouldn't want to use it for a true server, becuase who wants their server IP to change when a NIC burns out?
All that said, in a dual-stack environment it works reasonably well: but it doesn't honestly look like anyone gave much thought to a time when IPv4 wouldn't be present on the LAN or on the hosts...
Re:Missing DNS (Score:5, Informative)
Eh, what?
As far as I could tell, as soon as I started radvd on my gateway all my xen guests autoconfigured their global v6 address. Perhaps you have a VMWare specific issue?
"4) Obviously you wouldn't want to use it for a true server, becuase who wants their server IP to change when a NIC burns out?"
Obviously you dont have a server-hardware ip address to use for a true server service. You dedicate an IP address to the actual service so you can move it around freely decoupled from the hardware and any other services on the box. (And to tie back to your earlier point; if you're virtualizing, there's no connection between the hardware and the MAC address anyway).
When you have a bazillion ip addresses it's not like you have to save them for a rainy day.
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Re: (Score:2)
You do have a fair point: I should probably consider that a VMWare issue rather than an autoconf issue, but the general v6 approach is to have a single gigantic broadcast domain per "site," instead of learning the lessons we all have in the past 10 years about the benefits of small layer-2 islands connected with layer-3... So
Re: (Score:3, Insightful)
Could be a bridging issue with VMWare. As long as the virtualization software acts as an unfiltered bridge, v6 autoconf really should work.
"instead of learning the lessons we all have in the past 10 years about the benefits of small layer-2 islands connected with layer-3."
I agree in part, but it depends on how you look at it. I think the idea is to use it as huge, very sparsely populated layer-2 islands conne
wasn't going to use it anyway..... (Score:5, Interesting)
Most people think of DHCP as just giving an IP address, mask, gateway, and DNS. DHCP can do SO much more. We're talking HUNDREDS of pieces of data, including custom strings. Want to tell your IP phone where the call manager is? DHCP. Want to tell your Netware clients where the nearest replica server is? DHCP. Still using WINS for some strange reason? DHCP.
Autoconfig is nice for the lazy admin, but for folks who want to keep track of where their IPs are going and want to deploy additional features, DHCP is the better option.
Re:wasn't going to use it anyway..... (Score:5, Informative)
IPv6 Anycast returns the nearest server that supports the capability you want. True, you wouldn't use the router advertisement protocol, but there are major advantages to having lightweight protocols that can be added to as extra needs develop, as opposed to having one monolithic protocol that requires excessive space on the network and heavyweight processes to churn over.
Parent
Re: (Score:3, Interesting)
Not just corporate (Score:5, Informative)
There have been a number of suggestions to solve it that problem, of course, ranging from adding an extra field for DNS servers in the autoconfig ICMP messages to using well-known unicast addresses for the closest recursive DNS server to using a dedicated protocol just to discover DNS servers. The first and last of those have (rightfully, IMNSHO) been shot down because then one might "just as well" use DHCP, which exists and has a solution ready for the issue at hand. I cannot remember why the unicast suggestions have been rejected, though, and it has been disturbing me, because I think it is the best solution. I really just cannot see the drawbacks to it. I guess there might have been some talk about lack of security in that model, but that's a problem with DNS in general, though. That's why DNSSEC was invented.
Last I looked, the consensus seems to be to use autoconfig for address generation, and then request network information (such as DNS servers) from a link-local DHCPv6 server. When everything comes around, I think that's a rather good solution. Clients can still get whatever non-occupied address they want (which means the privacy extensions will also continue to work), and still get the information they find relevant, and a DHCPv6 server should be easy to implement on a network of any scale.
Agreed... Re:Not just corporate (Score:2, Interesting)
Why Not Both (Score:5, Insightful)
OK let me get this straight... (Score:5, Insightful)
O.O *blink blink* O.O
The real reason... (Score:3, Insightful)
1. They have run out of IP addresses ( remember the 10.0.0.0 private network is pretty big! )
2. Everyone else is doing it.
Option 1 is only really going to be a problem for the really big firms, and they will be really careful. All those Corporate apps need retesting with the new IP addresses, and that is a non trivial exercise ( think Y2K all over again!, except you could do it piecemeal ). It's a hard sell to the business : Mr PHB, we'd like to spend a large amount of money retesting all the applications in Globocorp to use a new IP numbering scheme. Nope, you won't get any business benefit.
ISPs may force people of IPv6 at some point, but that's only been an issue in South Korea so far. Everyone else still has enough IP addresses right now.
And until we get a critical mass of people going for Option 1, option 2 is a no go.
Choosing a story title... (Score:5, Informative)
One Less Reason to Adopt IPv6
IPv6 Address Assignment Choices
Some May Forgo IPv6 Autoconf. for DHCP
IPv6 Autoconf. Vs DHCPv6
NetworkWorld chic: Well, I like "33% Pointless" the best, but my editor struck it down. The informative ones are too boring. I'll get more page views with "One Less Reason..."
Headline backwards? (Score:2)
Stop making excuses! (Score:4, Funny)
It is going to have to happen and the longer we put it off the more expensive it is going to get over time to replace all the equipment. Yes, NAT works but its like trying to keep an old system road infrastructure in place that will be more costly to maintain at a certain point than to replace.
Re: (Score:3, Funny)
And NAT works very well as the poor man's firewall. Broadband routers have prevented more worm/virus outbreaks than any patch ever will.
address space (Score:5, Interesting)
a gargantuan address space,
Methinks one reason IPv6 hasn't been adopted is because those who have chunks of the IPv4 space are quite happy having what is essentially an artificially precious resource.
Most people think the IP address space is "nearly full", but a handful of companies are sitting on prime real estate (nevermind there is a huge amount of "reserved" space which is not in use.) For example, why do the following companies have entire class A's to themselves?
Re: (Score:3, Informative)
Too much magic (Score:3, Insightful)
I'm not sure if autoconf and IPv6 addresses in general have too much or too little magic. Admittedly, these are in part Linux implementation bugs, but the kitchen sink nature of v6 sure isn't helping. If I can't reach anything by v6, I don't really care that I can secure my connection to nowhere with crypto.
On the too much magic side, I announced 5001::/64 on my LAN at home as a test. Yet, when I try to go to a v6 enabled site, firefox tries to use v6 even though 5001::0/64 in no way impleis that I can reach 2001:: from here.
On the too little magic side, some sites have more than one router (It's called a private network, some people don't care to splatter their private business all over the world). I tried setting that up with both overlapping and non-overlapping prefixes. Neither worked at all. The machines bounced from one to another so that they didn't even keep a consistant address. Good thing I had v4 so I could fix it without hopping from machine to machine. Possible good behaviours might have been:
The success or failure of v6 will be in client support. Nobody is going to accept a v6 only web server if clients can't reach it. Many of those clients have v4 only ISPs with dynamic IPs. They will not want their entire lan to renumber every time they get a new dynamic assignment. So, they will want a non-routable prefix for local to local traffic. Too bad the silly machines will try to use that for non-local traffic!
Admins are often busy people. They don't want to devote their professional life to a v6 rollout, especially when practically nothing out there is reachable by v6 yet. If it's not dead simple it won't happen at all. I tried dead simple and as a result some sites became unreachable. I killed it again and they came back (falling back to their v4 addresses).
Link local addresses don't seem to work AT ALL. I see the route but I get EINVAL if I try to ping.
I suppose my next attempt will be to rip all the autoconfig stuff out of the kernel and implement a userspace daemon. It doesn't really belong in the kernel anyway. That's what initramfs is for.
In general, this business of having to add one of 6, -6, -A inet6 or other junk to the command line or appending a 6 to the name of the utility has got to go. It's one thing to need a software update to handle v6, I can understand that older software might not even know v6 exists, but the v6 version has no excuse for not knowing v4 exists. ping6 192.168.2.1: unknown host.
All of this tells me that v6 still has the status of a toy to play around with, not a supported standard ready for worldwide use. That's fine as far as it goes, but it's not exactly making people anxious to get on with the upgrade.
It's been over a decade now. Let's quit pretending it's just inertia and try to address the real adoption barriers while there are still v4 addresses left.
My advice:
Just forget about scope. Prefix lengths are more than adequate for making routing decisions.
Quit appending a 6 to everything (this is not marketing!). That includes structs and function calls in the library. For the most part, a v6 address as ASCII is distinguishable from v4. Likewise, in binary 4 octets followed by nulls or nulls followed by 4 octets is a v4 address. An app that won't run when the size of sockaddr_in changes was wrong to begin with. If you must, make -DV4ONLY use the old v4 only structs etc so broken source will compile and run. Done right, a number of old but well written programs could support v6 just by recompiling.
Allow multiple router announcements and behave gracefully. Use the prefix that best matches the destination.
Simpler handling of 6to4 and 4to6 translations. With so many people using APs and other routers for a broadband connection now, automatic en/de-capsulation in IPv4 can go a long way with very little configuration and a few simple rules.
Re:Whatever Works (Score:5, Insightful)
Parent
Re:Whatever Works (Score:5, Insightful)
Because that's just human nature -- we're all procrastinators -- some of us admit it -- others are putting that admission off.
History is replete with situations where timely action would have saved piles of money and/or lives -- have we ever acted at the right time? No -- we wait until something like http://www.historyplace.com/worldwar2/timeline/dday.htm [historyplace.com] is necessary.
So I think we can all safely predict that it will be a crisis before we do anything about it.
And remember -- never put off until tomorrow that which can be put off until the day after.
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Re:Whatever Works (Score:4, Insightful)
Because until it's a crisis, you can't get the money to upgrade. If current addressing is going to work for another week, then it costs nothing to stick with it. Call me when the crisis is imminent.
Parent
Crisis, what crisis? (Score:5, Insightful)
Nothing happened.
So the accepted wisdom became that the whole thing was just an alarmist fiasco that chewed up a bunch of money unnecessarily. They don't realize that y2k was no problem precisely because of all the noise. A LOT of people did a lot of planning and a lot of work, and that all paid off in how few problems there really were.
But the common man, and unfortunately the common leaders don't understand that. So now y2k was a so-called crisis, wasn't a problem, and we can approach our next so-called crisis without the extensive preparation we "wasted" on y2k. Oh boy!
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Re:Crisis, what crisis? (Score:5, Interesting)
Yup. I hate to say it, but I was kind of hoping we'd see one nuclear silo launch and drop a nuke harmlessly into the ocean just to remind people of how f*cked we could have been.
Parent
Re:Whatever Works (Score:5, Funny)
Ironically, the longer you wait to deal with it, the cheaper it may be!
There are some obvious reasons why waiting longer makes it cost more, but there are quite a few subtle reasons why it's cheaper to wait. For example:
1) If your current hardware is not IPv6 capable and you buy new IPv6-capable hardware now, it may reach end-of-life before you need the IPv6 capability.
2) IPv6 routes take more memory than IPv4 routes. The longer you wait, the cheaper it will be to add this memory. (Note that we're not just talking cheap main memory, we're talking expensive CAM and custom chip memory.)
3) Research and development are constantly progressing. The longer you wait, the better researched the solution you ultimately deploy may be. (To a limit, of course. You also lose the chance to gain experience.)
On balance, I think we're progressing at a sensible pace, perhaps a bit slower than perfect. People are continuing to do test deployments to see how IPv6 will work and make sure they'll be able to implement it for real when the demand comes. But they're not wasting money replacing working hardware or increasing network instability on the real, live Internet we all depend on for our daily (hourly? half-hourly?)
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Re:Um,... it has to be said. (Score:5, Informative)
http://www.networkworld.com/cgi-bin/mailto/x.cgi?pagetosend=/export/home/httpd/htdocs/news/2007/091107-dhcpv6.html [networkworld.com]
Parent
Re: (Score:3, Interesting)