SLAAC May Save Your Life

Flatline

A chance dinner conversation at Wireless Field Day 7 with George Stefanick (@WirelesssGuru) and Stewart Goumans (@WirelessStew) made me think about the implications of IPv6 in healthcare.  IPv6 adoption hasn’t been very widespread, thanks in part to the large number of embedded devices that have basic connectivity.  Basic in this case means “connected with an IPv4 address”.  But that address can lead to some complications if you aren’t careful.

In a hospital environment, the units that handle medicine dosing are connected to the network.  This allows the staff to program them to properly dispense medications to patients.  Given an IP address in a room, staff can ensure that a patient is getting just the right amount of painkillers and not an overdose.  Ensuring a device gets the same IP each time is critical to making this process work.  According to George, he has recommended that the staff stop using DHCP to automatically assign addresses and instead move to static IP configuration to ensure there isn’t a situation where a patient inadvertently receives a fatal megadose of medication, such as when an adult med unit is accidentally used in a pediatric application.

This static policy does lead to network complications.  Units removed from their proper location are rendered unusable because of the wrong IP.  Worse yet, since those units don’t check in with the central system any more, they could conceivably be incorrectly configured.  At best this will generate a support call to the IT staff.  At worst…well, think lawsuit.  Not to mention what happens if there is a major change to gateway information.  That would necessitate massive manual reconfiguration and downtime until those units can be fixed.

Cut Me Some SLAAC

This is where IPv6 comes into play, especially with Stateless Address Auto Configuration (SLAAC).  By using an automatically configured address structure that never changes, this equipment will never go offline.  It will always be checked in on the network.  There will be little chance of the unit dispensing the wrong amount of medication.  The medical unit will have history available via the same IPv6 address.

There are challenges to be sure.  IPv6 support isn’t cheap or easy.  In the medical industry, innovation happens at a snail’s pace.  These devices are just now starting to have mobile connectivity for wireless use.  Asking the manufacturers to add IPv6 into their networking stacks is going to take years of development at best.

Having the equipment attached all the time also brings up issues with moving the unit to the wrong area and potentially creating a fatal situation.  Thankfully, the router advertisements can help there.  If the RA for a given subnet locks the unit into a given prefix, controls can be enacted on the central system to ensure that devices in that prefix range will never be allowed to dispense medication above or below a certain amount.  While this is more of a configuration on the medical unit side, IPv6 provides the predictability needed to ensure those devices can be found and cataloged.  Since a SLAAC addressed device using EUI-64 will always get the same address, you never have to guess which device got a specific address.  You will always know from the last 64 bits which device you are speaking to, no matter the prefix.

Tom’s Take

Healthcare is a very static industry when it comes to innovation.  Medical companies are trying to keep pace with technology advances while at the same time ensuring that devices are safe and do not threaten the patients they are supposed to protect.  IPv6 can give us an extra measure of safety by ensure devices receive the same address every time.  IPv6 also gives the consistency needed to compile proper reporting about the operation of a device and even the capability of finding that device when it is moved to an improper location.  Thanks to SLAAC and IPv6, one day these networking technologies might just save your life.

IPv6 and the VCR

IPv6 isn’t a fad.  It’s not a passing trend that will be gone tomorrow.  When Vint Cerf is on a nationally televised non-technical program talking about IPv6 that’s about as real as it’s going to get.  Add in the final depletion of IPv4 address space from the RIRs and you will see that IPv6 is a necessity.  Yet there are still people in tech that deny the increasing need for IPv6 awareness.  Those same people that say it’s not ready or that it costs too much.  It reminds me of a different argument.

IPvcr4

My house is full of technology.  Especially when it comes to movie watching.  I have DVRs for watching television, a Roku for other services, and apps on my tablet so the kids can watch media on demand.  I have a DVD player in almost every room of the house.  I also have a VCR.  It serves one purpose – to watch two movies that are only available on a video tape.  Those two movies are my wedding and the birth of my oldest son.

At first, the VCR stated connected to our television all the time.  We had some movies that we owned on VHS that we didn’t have DVD or digital copies.  As time wore on, those VHS movies were replaced by digital means.  Soon, the VCR only served to enable viewing of the aforementioned personal media.  We couldn’t get that on a DVD from just anywhere.  But the VCR stayed connected for those occasions when the movies needed to be watched.  Soon, it was too much of a hassle to reconnect the VCR, even for these family films.  Eventually, we figured out how to hook up the VCR and record the content into a digital format that’s available from non-analog sources.

How does this compare to IPv6?  Most people assume that the transition to IPv6 from IPv4 will be sudden and swift.  They will wake up one morning and find that all their servers and desktops are running global IPv6 addresses and IPv4 will be a distant memory.  In fact, nothing can be further from the truth.  IPv4 and IPv6 can coexist on the same system.  IPv6 can be implemented alongside IPv4 without disrupting connectivity.  As in the above example, you can watch DVDs and VHS tapes on the same TV without disruption.

As IPv4 address availability is restricted, may engineers will find themselves scrambling to replace existing systems and deploy new ones without access to IPv4 addresses.  That’s when the real cutover begins.  As these new systems are brought online, IPv6 will be the only address space available.  These systems will be connected with IPv6 first and provisions will be made for them to connect to other systems via IPv4.  Eventually, IPv4 will only exist for legacy systems that can’t be upgraded or migrated.  Just like the VCR above, it will only be needed for a handful of operations.

We never have to reach a point where IPv4 will be completely eliminated.  IPv4-only hosts will still be able to connect to one another so long as the global IPv4 routing table is available.  It may be reduced in size as IPv6 gains greater adoption, but it will never truly go away.  Instead, it will be like IBM’s SNA protocol.  Relevant to a few isolated hosts at best.  The world will move on and IPv6 will be the first choice for connectivity.


 Tom’s Take

I must admit that this idea was fostered from a conversation with Ed Horley (@EHorley).  The evangelism that he’s doing with both the CAv6TF and the RMv6TF is unparalleled.  They are doing their best to get the word out about IPv6 adoption.  I think it’s important for people in tech to know that IPv6 isn’t displacing IPv4.  It’s extending network functionality. It’s granting a new lease on life for systems desperately in need of address space.  And it allows IPv4-only systems to survive a little while longer.  You don’t have to watch the same old VHS tapes every day.  But you don’t have to leave the IPvcr4 hooked up all the time either.

Betting the Farm on IPv6

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IPv6 seems to have taken a back seat to discussions about more marketing-friendly topics like software defined networking and the Internet of Things.  People have said that IPv6 is an integral part of these initiatives and any discussion of them implies IPv6 use.  Yet, as I look around at discussions about SDN host routes or NATed devices running home automation for washing machines and refrigerators, I wonder if people really understand the fundamental shift in thinking.

One area that I recently learned has been investing heavily in IPv6 is agriculture.  When people think of a farm, they tend to imagine someone in a field with a plow being pulled by a horse.  Or, in a more modern environment you might imagine a tractor pulling a huge disc plow across hundreds of acres of fallow land.  The reality of faming today is as far removed from the second example as the second example is from the first.

Farming In The East

Modern farmers embrace all kinds of technology to assist in providing maximum yields, both in the western world as well as the east.  The biggest strides in information technology assistance for farmers has been in East Asia.  Especially in China, a country that has to produce massive amounts of food to feed 1.3 billion people.

Chinese farmers have embraced technologies that allow them to increase productivity.  Think about how many tractors are necessary to cultivate the huge amount of land needed to grow food.  Each of those tractors now comes equipped with a GPS transmitter capable of relaying exact positioning.  This ensures the right land is being worked and the area is ideal for planting certain types of crops.  All that telemetry data needs to be accumulated somewhere in order to analyze and give recommendations.

Think also about livestock.  In the old days, people hired workers to ensure that livestock didn’t escape or wander away from the herd.  It was a process that was both time and labor intensive.  With modern technology, those same cattle can be tagged with a small GPS transmitter.  A system can poll each animal in a given interval to determine herd count and location.  Geofences can be erected to ensure that no animal moves outside of a safe area.  When that occurs, alarms can be sent to monitoring stations where a smaller number of farm hands can drive out and rescue the errant animal.

Those two examples alone show the power of integrating traditional agriculture with information technology.  However, an unstated problem does exist: Where are we going to get those addresses?  We joke about giving addresses to game consoles and television sets and how that’s depleting the global IPv4 pool.  What happens when I do the same to dairy farmer’s herd?  Even my uncle and his modest dairy years ago had around one hundred cattle in his herd.  What happens when your herd is bigger than a /24?

IPv6 Rides To The Rescue

China has already solved this problem.  They don’t have any more IPv4 prefixes available.  They have to connect their devices.  The only answer is IPv6.  Tractors can exist as IPv6 endpoints in the monitoring station.  They can be tracked globally via monitoring stations.  Farm workers and supervisors can determine where the unit is at any given time.  Maintenance information can be relayed back to the manufacturer to alert when a part is on the verge of failure.  Heavy equipment can stay in working condition longer and be used more efficiently with this type of tracking.

Livestock herds can be monitored for position to ensure they are not trespassing on another farmers land.  The same telemetry can be used to monitor vital statistics to discover when animals have become ill.  That allows the farm workers to isolate those animals to prevent the herd from contracting illness that will slow production or impact yields.  Keeping better track of these animals ensures they will be as productive as possible, whether that be in a dairy case or a butcher shop.


Tom’s Take

I grew up on a farm.  I have gathered eggs, bottle fed calves, and milked cows.  Two of my uncles owned dairies.  The biggest complaint that I’ve heard from them was the lack of information they had on their products.  Whether it be a wheat crop or a herd of dairy cattle, they always wanted to know more about their resources.  With IPv6, we can start connecting more and more things to the Internet to provide access to the data that’s been locked away for so long, inaccessible to the systems that can provide insight.  Advancing technology to the point where a tractor or a bull can have a 2001::/16 address is probably the safest bet a farmer will make in his entire career.

IPv4? That Will Cost You

ipvdollar

After my recent articles on Network Computing, I got an email from Fred Baker.  To say I was caught off guard was an understatement.  We proceeded to have a bit of back and forth about IPv6 deployment by enterprises.  Well, it was mostly me listening to Fred tell me what he sees in the real world.  I wrote about some of it over on Network Computing.

One thing that Fred mentioned in a paragraph got me thinking.  When I heard John Curran of ARIN speak at the Texas IPv6 Task Force meeting last December, he mentioned that the original plan for IPv6 (then IPng) deployment involved rolling it out in parallel with IPv4 slowly to ensure that we had all the kinks worked out before we ran out of IPv4 prefixes.  This was around the time the World Wide Web was starting to take off but before RFC 1918 and NAT extended the lifetime of IPv4.  Network engineers took a long hard look at the plans for IPv6 and rightfully concluded that it was more expensive to run IPv6 in conjunction with IPv4 and instead it was more time and cost effective to just keep running IPv4 until the day came that IPv6 transition was necessary.

You’ve probably heard me quote my old Intro to Database professor, Dr. Traci Carte.  One of my favorite lessons from her was “The only way to motivate people is by fear or by greed.”  Fred mentioned that an engineer at an ISP mentioned to him that he wanted to find a way to charge IPv4 costs back to the vendors.  This engineer wants to move to a pure IPv6 offering unless there is a protocol or service that requires IPv4.  In that case, he will be more than willing to enable it – for a cost.  That’s where the greed motivator comes into play.  Today, IPv6 is quickly becoming equivalent in cost to IPv4.  The increased complexity is balanced out by the lack of IPv4 prefixes.

What if we could unbalance the scales by increasing the cost of IPv4?  It doesn’t have to cost $1,000,000 per prefix.  But it does have to be a cost big enough to make people seriously question their use of IPv4.  Some protocols are never going to be ported to have IPv6 versions.  By making the cost of using them higher, ISPs and providers can force enterprises and small-to-medium enterprises (SMEs) to take a long hard look at why they are using a particular protocol and whether or not a new v6-enabled version would be a better use of resources.  In the end, cheaper complexity will win out over expensive ease.  The people in charge of the decisions don’t typically look at man-hours or support time.  They merely check the bottom line.  If that bottom line looks better with IPv6, then we all win in the end.

I know that some of you will say that this is a hair-brained idea.  I would counter with things like Carrier-Grade NAT (CGN).  CGN is an expensive, complicated solution that is guaranteed to break things, at least according to Verizon.  Why would you knowingly implement a hotfix to IPv4 knowing what will break simply to keep the status quo around for another year or two?  I would much rather invest the time and effort in a scaling solution that will be with us for another 10 years or more.  Yes, things my break by moving to IPv6.  But we can work those out through troubleshooting.  We know how things are supposed to work when everything is operating correctly.  Even in the best case CGN scenario we know a lot of things are going to break.  And end-to-end communications between nodes becomes one step further removed from the ideal.  If IPv4 continuance solutions are going to drain my time and effort they become as costly (or moreso) that implementing IPv6.  Again, those aren’t costs that are typically tracked by bean counters unless they are attached to a billable rate or to an opportunity cost of having good engineering talent unavailable for key projects.


Tom’s Take

Dr. Carte’s saying also included a final line about motivating people via a “well reasoned argument”.  As much as I love those, I think the time for reason is just about done.  We’ve cajoled and threatened all we can to convince people that the IPv4 sky has fallen.  I think maybe it’s time to start aiming for the pocketbook to get IPv6 moving.  While the numbers for IPv6 adoption are increasing, I’m afraid that if we rest on our laurels that there will be a plateau and eventually the momentum will be lost.  I would much rather spend my time scheming and planning to eradicate IPv4 through increased costs than I would trying to figure out how to make IPv4 coexist with IPv6 any longer.

IP Addresses in Entertainment

Fake IP

Every time I sit down to watch a TV show or movie and they mention computers or hacking, I get amused.  I know that I’m probably going to see some attempt to make computer hacking look cool or downright scary.  Whether it be highly stylized like Hackers or fairly accurate like the power plant hack in The Matrix Reloaded, there are always little details that get glossed over.  In many cases, one of these is the IP addressing of the systems themselves.  If the producers and writers of the film even choose to show an IP address on the screen, it’s usually so wrong that I laugh at a totally inappropriate moment of drama.

The practice of using fictitious numbering schemes for things in entertainment goes back several decades.  The first known instance of a movie using a fake number for something was in Panic in Year Zero back in 1962.  For the first time, the writers used a fictitious phone number starting with 555 instead of a real telephone number.  Even though 555 prefixes were used for things like directory assistance, they weren’t widely deployed.  As such, the 555 prefix became synonymous with a “fake” phone number.  555-0100 through 555-0199 are the only official numbers in that range set aside for fictitious use, however many people still associate that prefix with a phone number that won’t work in the real world.

Hollywood has been trying for some time to come up with IP addresses that look real enough to pass the sniff test but are totally false.  Sometimes that works.  Other times, you end up with Law and Order.  In particular, the SVU flavor of that show has been known to produce IP address ranges that don’t even come close to looking real.  This page documents a couple of the winners from that show when the police start tracing an offender by their IP address.  Some of them look almost real.  Others seem to have an octet that jumps above 255.  Still others have 4-digit octets or other oddities that don’t quite measure up.  Sure, it heightens the suspense when people can see what the detectives are doing, but for those of us that know enough to be dangerous, it pulls you out of the moment.  It would be like watching ER and hearing the doctors start talking about brain surgery, only to start cutting open a patient’s arm to get to it.

TCP/IP has a large number of address ranges that can be used in a fictitious manner. For instance, Class E experimental addresses (240.0.0.0/4) were set aside and hard coded into most OSes as unavailable.  The address range for example use and documentation purposes 192.0.2.0/24 can also serve as a safe fictitious range.  Then there’s RFC 1918.  These addresses are used for private network ranges and must be NATed to work correctly on the public internet due to their non-routability.  These would be perfect for use in movies, as they represent networks that most people use daily.  They would look believable to those of us that know what to look for.  However, I think the producers and writers avoid doing that because of the inherent curiosity of people.

The greatest example of this comes courtesy of Tommy Tutone.  The band hit radio gold with their song “867-5309/Jenny” back in 1982.  Unlike 555, 867 is a widely used prefix code in the North American Numbering Plan (NANP).  There are numerous stories of people that have received that phone number and been cursed with popularity.  One story from Brown university tells of unsuspecting freshmen that move into the dorm room with that telephone number.  The phone calls never stop until a request is made to shut down the line.  Even back in 1982, the regional Bell companies were seeing huge spikes in telephone calls to that one number.  In many cases, they had to disconnect it in order to keep the traffic to a reasonable level.  If you’re curious, you can hear some of the messages left for the unfortunate possessors of that cursed number over at http://www.jennynetwork.com

People are compelled to try things they see in movies.  This article in the Chicago Tribune talks about the writer memorizing a realistic looking number from a movie and going home to call it several times before giving up.  The movie Magnolia included the real number 877-TAME-HER which the movie studio used to record Tom Cruise giving an in-character speech about his system for the purposes of marketing.  That’s all well and good in the real world when someone gets a few occasional prank calls or other harmless issues.  What happens in a computer network when someone sees a 10.0.0.0/8 address on TV and then decides to try and hack it?  What if they call the police and say that the computer address of a murder or a predator is on their network?  This can cause huge issues for network admins.  The nightmare of trying to explain to people that just because the Gibson in Hackers 3 is at 192.168.1.2 doesn’t mean they get to assault the mail server every day would get old really fast.  And when it comes to IPv6, the opportunity for even more trouble arises.

I was a long-time player of the MMORPG City of Heroes.  One of the reasons that I liked playing it so much was the lore and back story to the world.  I was one of the players that read all of the fluff text to get a better sense of what the writers were trying to do.  Imagine my surprise when I was playing a new mission a several months ago and ran across a little Easter egg.  One of the writers decided that the imaginary world of Paragon City had long ago ran out of IPv4 addresses and decided to upgrade to IPv6.  One of the consoles in the game had a reference to an IPv6 address – 3015:db6:97c4:9e1:2420:9b3f:073:8347.  I was excited.  Finally, someone in the entertainment industry realized we were running out of IPv4!  Then I started thinking.  Right now, the allocations to the RIRs all start with 2001.  Eventually, once we get the intergalactic Internet up and running, we might end up getting into the 3000 range.  It might be a hundred years before the address above is allocated to someone.  By then, most everyone will have forgotten City of Heroes ever existed.  Putting real IPv6 addresses in movies and on TV does run the risk of having people “hacking the Gibson” when you least expect it.  I think you’ll see that even in those far-flung ranges, the odds of a fake address on TV coinciding with a real IPv6 server or workstation address, even on a global scale, is pretty slim.  Despite the fact that all our systems will be globally reachable, the IPv6 address space is so large that no two systems are likely to even overlap.  Add in neighbor discovery, duplicate address detection, and the uniqueness of a MAC address (which forms the basis of EUI-64 addressing and SLAAC) and you can see how difficult it would be.


Tom’s Take

In case the name of my blog didn’t warn you…I’m a nerd.  When I see something inaccurate in a movie, I tend to point it out.  That’s why I don’t watch Armageddon any more.  I understand that writers and directors are trying to entertain people.  When you’re trying to do that, sometimes the details get sacrificed for the sake of telling a good story.  However, when it comes to something that can represented easily for the most realistic look possible, the creative team involved should do that.  Whether it be the night sky in Titanic or the address of the mainframe in a techno thriller, I want the people that care about the production values of a movie to show me how much they care.  With the advent of IPv6, I think creating fake addresses to put in movies and other entertainment will be easier.  Given the vast range of available space it doesn’t take too much effort to pull out something “techy sounding” to put in a movie script.  Trust me, the nerds out there will thank you for it.

2012 Depleted, Time to Adopt ::2013

It’s been 366 days since my last post about goals for 2012.  How’d I do on my list for the past year?

1. Juniper – Dropped the ball on this one.  I spent more time seeing Juniper gear being installed all over the place and didn’t get my opportunity to fire up the JNCIA-Junos liked I wanted.  I’m planning to change all that sooner rather than later.  Doug Hanks even gave me a good head start on immersion learning of the MX Series.

2. Data Center – I did get a little more time on some Nexus gear, but not nearly enough to call it good for this goal.  Every time I sat down to start looking at UCS, I kept getting pulled away on some other project.  If the rumblings I’m hearing in the DC arena are close to accurate, I’m going to wish I’d spent more time on this.

3. Advanced Virtualization – While I didn’t get around to taking either of the VCAP tests in 2012, I did spend some more time on virtualization.  I was named a vExpert for 2012, gave a virtualization primer presentation, and even attended my first VMUG meeting.  I also started listening to the vBrownBag podcast put on by ProfessionalVMware.  They have a ton of material that I’m going to start reviewing so I can go out and at least take the DCD test soon.

4. Moving to the Cloud – Ah ha! At last something that I nailed.  I moved a lot of my documents and data into cloud-based storage.  I leveraged Dropbox, Skydrive, and Google Docs to keep my documentation consistent across multiple platforms.  As I continue forward, I’m going to keep storing my stuff in the big scary cloud so I can find it whenever I need it.

Looks like I’ve got two fails, one tie, and one win.  Still not the 50% that I had hoped for, but it’s funny how real life tends to pull you in a different direction that you anticipate.  Beyond attending a few more Tech Field Day events and Cisco Live, I also attended a Cisco Unified Communications Partner Beta Training launch event and the Texas IPv6 Task Force Winter Summit.  It was this last event that really got me thinking about what I wanted to do in the coming year.

I think that 2013 is going to be a huge year for IPv6 adoption on the Internet.  We’ve been living in the final depletion phase of IPv4 for a whole year now.  We can no longer ignore the fact that IPv6 is the future.  I think the major issue with IPv6 adoption is getting the word out to people.  Some of the best and brightest are doing their part to talk to people about enabling IPv6.  The Texas IPv6 Task Force meeting showed me that a lot of great people are putting in the time and effort to try and drive people into the future.  However, a lot of this discussion is happening outside of people’s view.  Mailing lists aren’t exactly browsing-friendly.  Not everyone can drop what they’re doing for a day or two to go to a task force meeting.  However, people do have the spare time to read a blog post on occasion.  That’s where I come in.

In 2013, I’m going to do my part to get the word out about IPv6.  I’m going to spend more time writing about it.  I’m going to write posts about enabling it on all manner of things.  Hypervisors, appliances, firewalls, routers, and even desktops are on the plate.  I want to take the things I’m learning about IPv6 and apply them to the world that I work in.  I don’t know how service providers are going to to enable IPv6.  However, I can talk about enabling CallManager to use IPv6 and register IP phones without IPv4 addresses.  I can work out the hard parts and the gotchas so that you won’t have to.  I’ve already decided that any presentation that I give in 2013 will be focused on IPv6.  I’ve already signed up for one slot later in the year with a possibility of having a second.  I applied for a presentation slot at the Rocky Mountain IPv6 Task Force meeting in April.  I want to hone my skills talking to people about IPv6.  I’m also going to try and make a lot more blog posts about IPv6 in the coming year.  I want to take away all the scary uncertainty behind the protocol and make it more agreeable to people that want to learn about it without getting scared off by the litany of RFCs surrounding it.  To that end, I’m going to start referring to this year as ::2013.  The more we get familiar with seeing IPv6 notation in our world, the better off we’ll be in the long run.  Plus, it gives me a tag that I can use to show how important IPv6 is to me.

A shorter set of goals this year doesn’t mean a more modest one.  Focus is a good thing in the long run for me.  Being an agent of change when it comes to IPv6 is something that I’m passionate about.  Sure, I’m still going to make the occasional NAT post.  I may even have some unnice things to say about vendors and IPv6 support.  The overall idea is that we keep the discussion focused on moving forward and making IPv6 more widely adopted.  It’s the least I can do to try and leave my mark on the Internet in some other way besides posting cat pictures or snarky memes.  It’s also a goal that is going to keep progressing and never really be finished until the lights are turned out on the last IPv4 webserver out there.  Until that fateful day, here’s hoping that ::2013 is a good year for all.

Unlearning IPv4

"You must unlearn what you have learned." -Yoda

“You must unlearn what you have learned.” -Yoda

As network rock stars, we’ve all spent the majority of our careers learning how to do things.  We learn how to address interfaces and configure routing protocols.  For many of those out there, technology has changed often enough that we often find ourselves need to retrain.  Whether it be a new version of an old protocol or an entirely new way of thinking about things, there will always come a time when it’s necessary to pick up new knowledge.  However, in the case of updated knowledge it’s often difficult to process.  That’s because the old way of doing things interposes itself in our brains while we’re learning to do it the new way.  How many times have you been practicing something only to hear a little voice in the back of your head saying, “That’s not right.  You should be doing it this way.”  In many ways, it’s like trying to reprogram the pathway in your brain that leads to the correct solution to your problem.

This is very apparent to me when it comes to learning how to configure and setup IPv6 on a network.  Those just starting out in the big wide world of IPv6 need to have some kind of reference point to start configuring things, so they tend to lean back on their IPv4 training in order to get started.  This can work for some applications.  For others, though, it can be quite detrimental to getting IPv6 running the way it should.  Instead of carrying forward the old way of doing things because “that’s just the way they should be done,” you need to start unlearning IPv4.  The little green guy in Empire Strikes Back hit the nail on the head.  The whiney farm boy had spent so much of his life convinced that something was impossible that he couldn’t conceive that someone could lift his starship out of a swamp with the Force.  He had to unlearn that lifting things with his mind was impossible.  Once you take that little step, nothing can stop you from accomplishing anything.

With that in mind, here are a few things that need to be unlearned from our days working with IPv4.  Note that this won’t be easy.  But nothing worth doing is ever easy.

Address Conservation – This one is the biggest stumbling block today.  Look at all the discussion we’ve got around point-to-point links and whether to address them with a /64 or a /127 bit mask.  People claim that addressing this link with a /64 wastes addresses.  To  quote the old guy in the desert from Star Wars, “It’s true, depending on your point of view.”  In a given /64, there are approximately 18 quadrillion addresses available (I’m rounding to make the math easy).  If you address a point-to-point link with a /64, you’re only going to be using 0.0000000000000000001% of those addresses (thats 1 * 10^-19).  To many, that’s a pretty big waste.  But with numbers that big, your frame of reference gets screwed up.  By example, take a subnet with 4,094 hosts, which today would need /20 in IPv4.  That’s about the biggest single subnet I can imagine creating.  If you address that 4,094 host subnet with a /64 in IPv6, you’d end up using 0.0000000000000002% (2 * 10^-16) of the address space.  Waste is all a matter of perspective.  On the other hand, by addressing a link with a bit mask beyond a /64, we break neighbor discovery and secure neighbor discovery and PIM sparse mode with embedded RP among other things.  We need to unlearn the address conservation mentality and instead concentrate on making our networks easier to configure and manage.

Memorizing IP addresses – I’m guilty of this.  I spend a lot of time working at the command line with IPv4, whether it be via telnet or SSH or even just plugging numbers into a GUI.  My CUCM systems are setup to use IP only.  I memorize the addresses of my servers, or in many cases try to make this as similar mnemonically to other systems to jog my memory about where to find them in IP space.  In IPv6, memorizing addresses is going to be impossible.  It’s hard enough for me to remember non-RFC1918 address space as it is with 4 octets of decimal numbers.  Now quadruple that and add in hex addressing.  And when it comes to workstations with SLAAC or DHCPv6 assigned addresses?  Forget about it.  Rather than memorizing address space, we’re going to need to start using DNS for communications between endpoints.  Yes, that means setting up DNS for all your routers and CUCM servers too.  It’s going to be a lot of extra work up front.  It’ll pay off in the long run, though.  I’m sure you’d much rather refer to CUCM1.local rather than trying to remember fe80::ba8d:12ff:fe0b:8aff every time you want to get to the phone server.

Subnet Masks – Never again will you need to see 255 in an IPv6 address unless it’s part of the address.  Subnet masking is dead and buried.  Instead, bit masks and slash notation rule the day.  This is going to be one of the most welcome changes in IPv6, but I think it’s going to take a long time to unlearn.  Not really as much for network engineers, but mainly for the people that have ancillary involvement with networking, such as the server people.  Think about the number of server admins that you’ve talked to that have memorized that the subnet mask of their network card is 255.255.255.0.  Now, ask them what that means. Odds are good they can’t tell you.  Worse, some of them might say that it’s a Class C subnet mask.  It’s a little piece of anecdotal information that they heard once when the network folks were talking that they just picked up.  Granted, most of the time the servers are going to be addresses with a /64 bit mask on the IPv6 address.  That’s still going to take a while to explain to the non-networking people.  No, you don’t need any more 255s in your address.  Yes, the /64 is the same as that, sort of.  No, there’s math involved.  Yes, I’ll take care of all the math.

Ships in the Night – As I said on my recent appearance on the Class C block podcast, I think it’s high time that networking vendors stop treating IPv4 and IPv6 like they are separate entities.  I know that I’ve spent the better part of this blog post talking about how IPv4 and IPv6 require a difference in application and not carrying across old habits and conventions.  The two protocols are more alike that they are different.  That means that we need to stop thinking of IPv6 as an afterthought.  Take a look at the CCIE.  There’s still a separate section for IPv6.  It feels like it was just a piece that was added on to the end of the exam instead of being integrated into the core lab.  Look at Kurt Bales’ review of the JNCIE lab that he took.  Specifically, the last bullet point.  You could be asked to configure something on either IPv4 or IPv6, or even both!  Juniper understands that the people taking the JNCIE today aren’t going to have the luxury of concentrating on just IPv4.  The world is going to require us to use IPv6, so I think it’s only fair that our certification programs start doing the same.  IPv6 should be integrated into every level of certification from CCNA/JNCIA all the way up to CCIE/JNCIE.


Tom’s Take

Working with IPv6 is a big change from the way we’ve done things in the past.  With SLAAC and integrated IPSec, the designers have done a great job of making our lives easier with things that we’ve needed for a long time.  However, we’re doing our best to preclude our transition to IPv6 by carrying over a lot of baggage from IPv4.  I know that our brains look for patterns and like to settle on familiarity as a way to help train for new challenges.  If we aren’t careful, we’re going to carry over too much of the old familiar networking and make IPv6 difficult to work with.  Unlearning what we think we know about networking is a good first step.  A person may learn something quickly with familiarity, but they can learn even faster when they approach it with a blank slate and a keen interest to learn.  With that approach, even the impossible won’t keep you from succeeding.