Overlay Transport and Delivery

amazon-com-boxes

The difference between overlay networks and underlay networks still causes issues with engineers everywhere.  I keep trying to find a visualization that boils everything down to the basics that everyone can understand.  Thanks to the magic of online ordering, I think I’ve finally found it.

Candygram for Mongo

Everyone on the planet has ordered something from Amazon (I hope).  It’s a very easy experience.  You click a few buttons, type in a credit card number, and a few days later a box of awesome shows up on your doorstep.  No fuss, no muss.  Things you want show up with no effort on your part.

Amazon is the world’s most well-known overlay network.  When you place an order, a point-to-point connection is created between you and Amazon.  Your item is tagged for delivery to your location.  It’s addressed properly and finds its way to you almost by magic.  You don’t have to worry about your location.  You can have things shipped to a home, a business, or a hotel lobby halfway across the country.  The magic of an overlay is that the packets are going to get delivered to the right spot no matter what.  You don’t need to worry about the addressing.

That’s not to say there isn’t some issue with the delivery.  With Amazon, you can pay for expedited delivery.  Amazon Prime members can get two-day shipping for a flat fee.  In overlays, your packets can take random paths depending on how the point-to-point connection is built.  You can pay to have a direct path provided the underlay cooperates with your wishes.  But unless a full mesh exists, your packet delivery is going to be at the mercy of the most optimized path.

Mongo Only Pawn In Game Of Life

Amazon only works because of the network of transports that live below it.  When you place an order, your package could be delivered any number of ways.  UPS, FedEx, DHL, and even the US Postal Service can be the final carrier for your package.  It’s all a matter of who can get your package there the fastest and the cheapest.  In many ways, the transport network is the underlay of physical shipping.

Routes are optimized for best forwarding.  So are UPS trucks.  Network conditions matter a lot to both packets and packages.  FedEx trucks stuck in traffic jams at rush hour don’t do much good.  Packets that traverse slow data center interconnects during heavy traffic volumes risk slow packet delivery.  And if the road conditions or cables are substandard?  The whole thing can fall apart in an instant.

Underlays are the foundation that higher order services are built on.  Amazon doesn’t care about roads.  But if their shipping times get drastically increased due to deteriorating roadways you can bet their going to get to the bottom of it.  Likewise, overlay networks don’t directly interact with the underlay but if packet delivery is impacted people are going to take a long hard look at what’s going on down below.

Tom’s Take

I love Amazon.  It beats shopping in big box stores and overpaying for things I use frequently.  But I realize that the infrastructure in place to support the behemoth that is Amazon is impressive.  Amazon only works because the transport system in place is optimized to the fullest.  UPS has a computer system that eliminates left turns from driver routes.  This saves fuel even if it means the routes are a bit longer.

Network overlays work the same way.  They have to rely on an optimized underlay or the whole system crashes in on itself.  Instead of worrying about the complexity of introducing an overlay on top of things, we need to work on optimizing the underlay to perform as quickly as possible.  When the underlay is optimized, the whole thing works better.

Is LISP The Answer to Multihoming?

LISPMultihoming

One of the biggest use cases for Locator/Identifier Separation Protocol (LISP) that will benefit small and medium enterprises is the ability to multihome to different service providers without needing to run Border Gateway Protocol (BGP). It’s the answer to a difficult and costly problem. But is it really the best solution?

Current SMB users may find themselves in a situation where they can’t run BGP. Perhaps their upstream ISP blocks the ability to establish a connection. In many cases, business class service is required with additional fees necessary to multihome. In order to take full advantage of independent links to different ISPs, two (or more) NAT configurations are required to send and receive packets correctly across the balanced connections. While technically feasible, it’s a mess to troubleshoot. It also doesn’t scale when multiple egress connections are configured. And more often that not, the configuration to make everything work correctly exists on a single router in the network, eliminating the advantages of multihoming.

LISP seeks to solve this by using a mapping database to send packets to the correct Ingress Tunnel Router (ITR) without the need for BGP. The diagram of a LISP packet looks a lot like an overlay. That’s because it is in many ways. The LISP packets are tunneled from an Egress Tunnel Router (ETR) to a LISP speaking decapsulation point. Depending on the deployment policies of LISP for a given ISP, it could be the next hop router on a connection. It could also be a router several hops upstream. LISP is capable of operating over non-LISP speaking connections, but it does eventually need decapsulation.

Where’s the Achille’s Heel in this design? LISP may solve the issue without BGP, but it does introduce the need for the LISP session to terminate on a single device (or perhaps a group of devices). This creates issues in the event the link goes down and the backup link needs to be brought online. That tunnel state won’t be preserved across the failover. It’s also a gamble to assume your ISP will support LISP. Many large ISPs should give you options to terminate LISP connections. But what about the smaller ISP that services many SMB companies? Does the local telephone company have the technical ability to configure a LISP connection? Let along making it redundant and highly available?

Right Tool For The Job

I think back to a lesson my father taught me about tools. He told me, “Son, you can use a screwdriver as a chisel if you try hard enough. But you’re better off spending the money to buy a chisel.” The argument against using BGP to multihome ISP connections has always come down to cost. I’ve gotten into heated discussions with people that always come back to the expense of upgrading to a business-class connection to run BGP or ensure availability. NAT may allow you to multihome across two residential cable modems, but why do you need 99.999% uptime across those two if you’re not willing to pay for it?

LISP solves one issue only to introduce more. I see LISP being misused the same way NAT has been. LISP was proposed by David Meyer to solve the exploding IPv4 routing table and the specter of an out-of-control IPv6 routing table.  While multihoming is certainly another function that it can serve, I don’t think that was Meyer’s original idea.  BGP might not be perfect, but it’s what we’ve got.  We’ve been using it for a while and it seems to get the job done.  LISP isn’t going to replace BGP by a long shot.  All you have to do it look at LISP ALternate Topology (LISP-ALT), which was the first iteration of the mapping database before the current LISP-TREE.  Guess what LISP-ALT used for mapping?  That’s right, BGP.


Tom’s Take

LISP multihoming for IPv4 or IPv6 in SMEs isn’t going to fix the problem we have today with trying to create redundancy from consumer-grade connections.  It is another overlay that will create some complexity and eventually not be adopted because there are still enough people out there that are willing to forgo an interesting idea simply because it came from Cisco.  IPv6 multihoming can be fixed at the protocol level.  Tuning router advertisements or configuring routes at the edge with BGP will get the job done, even if it isn’t as elegant as LISP.  Using the right tool for the right job is the way to make multihoming happen.

CCIE Version 5: Out With The Old

Cisco announced this week that they are upgrading the venerable CCIE certification to version five.  It’s been about three years since Cisco last refreshed the exam and several thousand people have gotten their digits.  However, technology marches on.  Cisco talked to several subject matter experts (SMEs) and decided that some changes were in order.  Here are a few of the ones that I found the most interesting.

CCIEv5 Lab Schedule

Time Is On My Side

The v5 lab exam has two pacing changes that reflect reality a bit better.  The first is the ability to take some extra time on the troubleshooting section.  One of my biggest peeves about the TS section was the hard 2-hour time limit.  One of my failing attempts had me right on the verge of solving an issue when the time limit slammed shut on me.  If I only had five more minutes, I could have solved that problem.  Now, I can take those five minutes.

The TS section has an available 30 minute overflow window that can be used to extend your time.  Be aware that time has to come from somewhere, since the overall exam is still eight hours.  You’re borrowing time from the configuration section.  Be sure you aren’t doing yourself a disservice at the beginning.  In many cases, the candidates know the lab config cold.  It’s the troubleshooting the need a little more time with.  This is a welcome change in my eyes.

Diagnostics

The biggest addition is the new 30-minute Diagnostic section.  Rather than focusing on problem solving, this section is more about problem determination.  There’s no CLI.  Only a set of artifacts from a system with a problem: emails, log files, etc.  The idea is that the CCIE candidate should be an expert at figuring out what is wrong, not just how to fix it.  This is more in line with the troubleshooting sections in the Voice and Security labs.  Parsing log files for errors is a much larger part of my time than implementing routing.  Teaching candidates what to look for will prevent problems in the future with newly minted CCIEs that can diagnose issues in front of customers.

Some are wondering if the Diagnostic section is going to be the new “weed out” addition, like the Open Ended Questions (OEQs) from v3 and early v4.  I see the Diagnostic section as an attempt to temper the CCIE with more real world needs.  While the exam has never been a test of ideal design, knowing how to fix a non-ideal design when problems occur is important.  Knowing how to find out what’s screwed up is the first step.  It’s high time people learned how to do that.

Be Careful What You Wish For

The CCIE v5 is seeing a lot of technology changes.  The written exam is getting a new section, Network Principles.  This serves to refocus candidates away from Cisco specific solutions and more toward making sure they are experts in networking.  There’s a lot of opportunity to reinforce networking here and not idle trivia about config minimums and maximums.  Let’s hope this pays off.

The content of the written is also being updated.  Cisco is going to make sure candidates know the difference between IOS and IOS XE.  Cisco Express Forwarding is going to get a focus, as is ISIS (again).  Given that ISIS is important in TRILL this could be an indication of where FabricPath development is headed.  The written is also getting more IPv6 topics.  I’ll cover IPv6 in just a bit.

The biggest change in content is the complete removal of frame relay.  It’s been banished to the same pile as ATM and ISDN.  No written, no lab.  In it’s place, we get Dynamic Multipoint VPN (DMVPN).  I’ve talked about why Frame Relay is on the lab before.  People still complained about it.  Now, you get your wish.  DMVPN with OSPF serves the same purpose as Frame Relay with OSPF.  It’s all about Stupid Router Tricks.  Using OSPF with DMVPN requires use of mGRE, which is a Non-Broadcast Multi-Access (NBMA) network.  Just like Frame Relay.  The fact that almost every guide today recommends you use EIGRP with DMVPN should tell you how hard it is to do.  And now you’re forced to use OSPF to simulate NBMA instead of Frame Relay.  Hope all you candidates are happy now.

vCCIE

The lab is also 100% virtual now.  No physical equipment in either the TS or lab config sections.  This is a big change.  Cisco wants to reduce the amount of equipment that needs to be physically present to build a lab.  They also want to be able to offer the lab in more places than San Jose and RTP.  Now, with everything being software, they could offer the lab at any secured PearsonVUE testing center.  They’ve tried in the past, but the access requirements caused some disaster.  Now, it’s all delivered in a browser window.  This will make remote labs possible.  I can see a huge expansion of the testing sites around the time of the launch.

This also means that hardware-specific questions are out.  Like layer 2 QoS on switches.  The last reason to have a physical switch (WRR and SRR queueing) is gone.  Now, all you are going to get quizzed on is software functionality.  Which probably means the loss of a few easy points.  With the removal of Frame Relay and L2 QoS, I bet that services section of the lab is going to be really fun now.

IPv6 Is Real

Now, for my favorite part.  The JNCIE has had a robust IPv6 section for years.  All routing protocols need to be configured for IPv4 and IPv6.  The CCIE has always had a separate IPv6 section.  Not any more.  Going forward in version 5, all routing tasks will be configured for v4 and v6.  Given that RIPng has been retired to the written exam only (finally), it’s a safe bet that you’re going to love working with OSPFv3 and EIGRP for IPv6.

I think it’s great that Cisco has finally caught up to the reality of the world.  If CCIEs are well versed in IPv6, we should start seeing adoption numbers rise significantly.  Ensuring that engineers know to configure v4 and v6 simultaneously means dual stack is going to be the preferred transition method.  The only IPv6-related thing that worries me is the inclusion of an item on the written exam: IPv6 Network Address Translation.  You all know I’m a huge fan of NAT.  Especially NAT66, which is what I’ve been told will be the tested knowledge.

Um, why?!? 

You’ve removed RIPng to the trivia section.  You collapsed multicast into the main routing portions.  You’re moving forward with IPv6 and making it a critical topic on the test.  And now you’re dredging up NAT?!? We don’t NAT IPv6.  Especially to another IPv6 address.  Unique Local Addresses (ULA) is about the only thing I could see using NAT66.  Ed Horley (@EHorley) thinks it’s a bad idea.  Ivan Pepelnjak (@IOSHints) doesn’t think fondly of it either, but admits it may have a use in SMBs.  And you want CCIEs and enterprise network engineers to understand it?  Why not use LISP instead?  Or maybe a better network design for enterprises that doesn’t need NAT66?  Next time you need an IPv6 SME to tell you how bad this idea is, call me.  I’ve got a list of people.


Tom’s Take

I’m glad to see the CCIE update.  Getting rid of Frame Relay and adding more IPv6 is a great thing.  I’m curious to see how the Diagnostic section will play out.  The flexible time for the TS section is way overdue.  The CCIE v5 looks to be pretty solid on paper.  People are going to start complaining about DMVPN.  Or the lack of SDN-related content.  Or the fact that EIGRP is still tested.  But overall, this update should carry the CCIE far enough into the future that we’ll see CCIE 60,000 before it’s refreshed again.

More CCIE v5 Coverage:

Bob McCouch (@BobMcCouch) – Some Thoughts on CCIE R&S v5

Anthony Burke (@Pandom_) – Cisco CCIE v5

Daniel Dib (@DanielDibSWE) – RS v5 – My Thoughts

INE – CCIE R&S Version 5 Updates Now Official

IPExpert – The CCIE Routing and Switching (R&S) 5.0 Lab Is FINALLY Here!

Avaya and the Magic of SPB

Avaya_logo-wpcf_200x57

I was very interested to hear from Avaya at Interop New York.  They were the company I knew the least about.  I knew the most about them from the VoIP side of the house, but they’ve been coming on strong with networking as well.  They are one of the biggest champions of 802.1aq, more commonly known as Shortest Path Bridging (SPB).  You may remember that I wrote a bit about SPB in the past and referred to it as the Betamax of networking fabric technologies.  After this presentation, I may be forced to eat my words to a degree.

Paul Unbehagen really did a great job with this presentation.  There were no slides, but he kept the attention of the crowd.  The whiteboard supported his message.  While informal, there was a lot of learning.  Paul knows SPB.  It’s always great to learn from someone that knows the protocol.

Multicast Magic

One of the things I keyed on during the presentation was the way that SPB deals with multicast.  Multicast is a huge factor in Ethernet today.  So much so that even the cheapest SOHO Ethernet switch has a ton of multicast optimization.  But multicast as implemented in enterprises is painful.  If you want to make an engineer’s blood run cold, walk up and whisper “PIM“.  If you want to watch a nervous breakdown happen in real time, follow that up with “RPF“.

RPF checks in multicast PIM routing are nightmarish.  It would be wonderful to get rid of RPF checks to eliminate any loops in the multicast routing table.  SPB accomplishes that by using a Dijkstra algorithm.  The same algorithm that OSPF and IS-IS use to compute paths.  Considering the heavily roots of IS-IS in SPB, that’s not surprising.  The use of Dijkstra means that additional receivers on a multicast tree don’t negatively effect the performance of path calculation.

I’ve Got My IS-IS On You

In fact, one of the optimized networks that Paul talked about involved surveillance equipment.  Video surveillance units that send via multicast have numerous endpoints and only a couple of receivers on the network.  In other words, the exact opposite problem multicast was designed to solve.  Yet, with SPB you can create multicast distribution networks that allow additional end nodes to attach to a common point rather than talking back to a rendezvous point (RP) and getting the correct tree structure from there.  That means fast convergence and simple node addition.

SPB has other benefits as well.  It supports 16.7 million ISIDs, which are much like VLANs or MPLS tags.  This means that networks can grow past the 4,096 VLAN limitation.  It looks a lot like VxLAN to me.  Except for the reliance on multicast and lack of a working implementation.  SPB allows you to use a locally significant VLAN for a service and then defined an ISID that will transport across the network to be decapsulated on the other side in a totally different VLAN that is attached to the ISID.  That kind of flexibility is key for deployments in existing, non-green field environments.

If you’d like to learn more about Avaya and their SPB technology, you can check them out at http://www.avaya.com.  You can also follow them on Twitter as @Avaya.


Tom’s Take

Paul said that 95% of all SPB implementations are in the enterprise.  That shocked me a bit, as I always thought of SPB as a service provider protocol.  I think the key comes down to something Paul said in the video.  When we are faced with applications or additional complexity today, we tend to just throw more headers at the problem.  We figured that wrapping the whole mess in a new tag or a new tunnel will take care of everything.  At least until it all collapses into a puddle.  Avaya’s approach with SPB was to go back down to the lower layers and change the architecture of things to optimize everything and make it work the right way on all kinds of existing hardware.  To quote Paul, “In the IEEE, we don’t build things for the fun it.”  That means SPB has their feet grounded in the right place.  Considering how difficult things can be in data center networking, that’s magical indeed.

Tech Field Day Disclaimer

Avaya was a presenter at the Tech Field Day Interop Roundtable.  They did not ask for any consideration in the writing of this review nor were they promised any.  The conclusions and analysis contained in this post are mine and mine alone.

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.

Accelerating E-Rate

ERateSpeed

Right after I left my job working for a VAR that focused on K-12 education and the federal E-Rate program a funny thing happened.  The president gave a speech where he talked about the need for schools to get higher speed links to the Internet in order to take advantage of new technology shifts like cloud computing.  He called for the FCC and the Universal Service Administration Company (USAC) to overhaul the E-Rate program to fix deficiencies that have cropped up in the last few years.  In the last couple of weeks a fact sheet was released by the FCC to outline some of the proposed changes.  It was like a breath of fresh air.

Getting Up To Speed

The largest shift in E-Rate funding in the last two years has been in applying for faster Internet circuits.  Schools are realizing that it’s cheaper to host servers offsite either with software vendors or in clouds like AWS than it is to apply for funding that may never come and buy equipment that will be outdated before it ships.  The limiting factor has been with the Internet connection of these schools.  Many of them are running serial T-1 circuits even today.  They are cheap and easy to install.  Enterprising ISPs have even started creating multilink PPP connections with several T-1 links to create aggregate bandwidth approaching that of fiber connections.

Fiber is the future of connectivity for schools.  By running a buried fiber to a school district, the ISP can gradually increase the circuit bandwidth as a school increases needs.  For many schools around the country that could include online testing mandates, flipped classrooms, and even remote learning via technologies like Telepresence.  Fiber runs from ISPs aren’t cheap.  They are so expensive right now that the majority of funding for the current year’s E-Rate is going to go to faster ISP connections under Priority 1 funding.  That leaves precious little money left over to fund Priority 2 equipment.  A former customer of mine spent the Priority 1 money to get a 10Gbit Internet circuit and then couldn’t afford a router to hook up to it because of the lack of money leftover for Priority 2.

The proposed E-Rate changes will hopefully fix some of those issues.  The changes call for  simplification of the rules regarding deployments that will hopefully drive new fiber construction.  I’m hoping this means that they will do away with the “dark fiber” rule that has been in place for so many years.  Previously, you could only run fiber between sites if it was lit on both ends and in use.  This discouraged the use of spare fiber, or dark fiber, because it couldn’t be claimed under E-Rate if it wasn’t passing traffic.  This has led to a large amount of ISP-owned circuits being used for managed WAN connections.  A very few schools that were on the cutting edge years ago managed to get dedicated point-to-point fiber runs.  In addition, the order calls for prioritizing funding for fiber deployments that will drive higher speeds and long-term efficiency.  This should enable schools to do away with running multimode fiber simply because it is cheap and instead give preferential treatment to single mode fiber that is capable of running gigabit and 10gig over long distances.  It should also be helpful to VARs that are poised to replace aging multimode fiber plants.

Classroom Mobility

WAN circuits aren’t the only technology that will benefit from these E-Rate changes.  The order calls for a focus on ensuring that schools and libraries gain access to high speed wireless networks for users.  This has a lot to do with the explosion of personal tablet and laptop devices as opposed to desktop labs.  When I first started working with schools more than a decade ago it was considered cutting edge to have a teacher computer and a student desktop in the classroom.  Today, tablet carts and one-to-one programs ensure that almost every student has access to some sort of device for research and learning.  That means that schools are going to need real enterprise wireless networks.  Sadly, many of them that either don’t qualify for E-Rate or can’t get enough funding settle for SMB/SOHO wireless devices that have been purchase for office supply stores simply because they are inexpensive.  It causes the IT admins to spend entirely too much time troubleshooting these connections and distracting them from other, more important issues. It think this focus on wireless will go a long way to helping alleviate connectivity issues for schools of all sizes.

Finally, the FCC has ordered that the document submission process be modernized to include electronic filing options and that older technologies be phased out of the program. This should lead to fewer mistakes in the filing process as well as more rapid decisions for appropriate technology responses.  No longer do schools need to concern themselves with whether or not they need directory assistance on their Priority 1 phone lines.  Instead, they can focus on their problem areas and get what they need quickly.  There is also talk of fixing the audit and appeals process as well as speeding the deployment of funds.  As anyone that has worked with E-Rate will attest, the bureaucracy surrounding the program is difficult for anyone but the most seasoned professionals.  Even the E-Rate wizards have problems from year to year figuring out when an application will be approved or whether or not an audit will take place.  Making these processes easier and more transparent will be good for everyone involved in the program.


Tom’s Take

I posted previously that the cloud would kill the E-Rate program as we know it.  It appears I was right from a certain point of view.  Mobility and the cloud have both caused the E-Rate program to be evaluated and overhauled to address the changes in technology that are now filtering into schools from the corporate sector.  Someone was finally paying attention and figured out that we need to address faster Internet circuits and wireless connectivity instead of DNS servers and more cabling for nonexistent desktops.  Taking these steps shows that there is still life left in the E-Rate program and its ability to help schools.  I still say that USAC needs to boost the funding considerably to help more schools all over the country.  I’m hoping that once the changes in the FCC order go through that more money will be poured into the program and our children can reap the benefits for years to come.

Disclaimer

I used to work for a VAR that did a great deal of E-Rate business.  I don’t work for them any longer.  This post is my work and does not reflect the opinion of any education VAR that I have talked to or have been previously affiliated with.  I say this because the Schools and Libraries Division (SLD) of USAC, which is the enforcement and auditing arm, can be a bit vindictive at times when it comes to criticism.  I don’t want anyone at my previous employer to suffer because I decided to speak my mind.

Brocade’s Pragmatically Defined Network

logo-brocadeMost of the readers of my blog would agree that there is a lot of discussion in the networking world today about software defined networking (SDN) and the various parts and pieces that make up that umbrella term.  There’s argument over what SDN really is, from programmability to orchestration to network function virtualization (NFV).  Vendors are doing their part to take advantage of some, all, or in some cases none of the above to push a particular buzzword strategy to customers.  I like to make sure that everything is as clear as possible before I start discussing the pros and cons.  That’s why I jumped at the chance to get a briefing from Brocade around their new software and hardware releases that were announced on April 30th.

I spoke with Kelly Harrell, Brocade’s new vice president and general manager of the Software Business Unit.  If that name sounds somewhat familiar, it might be because Mr. Harrell was formerly at Vyatta, the software router company that was acquired by Brocade last year.  We walked through a presentation and discussion of the direction that Brocade is taking their software defined networking portfolio.  According to Brocade, the key is to be pragmatic about the new network.  New technologies and methodologies need to be introduced while at the same time keeping in mind that those ideas must be implemented somehow.  I think that a large amount of the frustration with SDN today comes from a lot of vaporware presentations and pie-in-the-sky ideas that aren’t slated to come to fruition for months.  Instead, Brocade talked to me about real products and use cases that should be shipping very soon, if not already.

The key to Brocade is to balance SDN against network function virtualization, something I referred to a bit in my Network Field Day 5 post about Brocade.  Back then, I called NFV “Networking Done (by) Software,” which was my sad attempt to point out how NFV is just the opposite of what I see SDN becoming.  During our discussion, Harrell pointed out that NFV and SDN aren’t totally dissimilar after all.  Both are designed to increase the agility with which a company can execute on strategy and create value for shareholders.  SDN is primarily focused on programmability and orchestration.  NFV is tied more toward lowering costs by implementing existing technology in a flexible way.

NFV seeks to take existing appliances that have been doing tasks, such as load balancers or routers, and free their workloads from being tied to a specific piece of hardware.  In fact, there has been an explosion of these types of migrations from a variety of vendors.  People are virtualizing entire business lines in an effort to remove the reliance on specialized hardware or reduce the ongoing support costs.  Brocade is seeking to do this with two platforms right now.  The first is the Vyatta vRouter, which is the extension what came over in the Vyatta acquisition.  It’s a router and a firewall and even a virtual private networking (VPN) device that can run on just about anything.  It is hypervisor agnostic and cloud platform agnostic as well.  The idea is that Brocade can include a copy of the vRouter with application packages that can be downloaded from an enterprise cloud app store.  Once downloaded and installed, the vRouter can be fired up and pull a predefined configuration from the scripts included in the box.  By making it agnostic to the underlying platform, there’s no worry about support down the road.

The second NFV platform Brocade told me about is the virtual ADX application delivery switch.  It’s basically a software load balancer.  That’s not really the key point of the whole idea of applying the NFV template to an existing hardware platform.  Instead, the idea is that we’re taking something that’s been historically huge and hard to manage and moving it closer to the edge where it can be of better use.  Rather that sticking a huge load balancer at the entry point to the data center to ensure that flows are separated, the vADX allows the load balancer to be deployed very close to the server or servers that need to have the information flow metered.  Now, the agility of SDN/NFV allows these software devices to be moved and reconfigured quickly without needing to worry about how much reprogramming is going to be necessary to pull the primary load balancer out or change a ton of rules to take reroute traffic to a vMotioned cluster.  In fact, I’m sure that we’re going to see a new definition of the “network edge” being to emerge as more software-based NFV devices begin to be deployed closer and closer to the devices that need them.

On the OpenFlow front, Brocade told me about their new push toward something they are calling “Hybrid Port OpenFlow.”  OpenFlow is a great disruptive SDN technology that is gaining traction today, largely in part because of companies like Brocade and NEC that have embraced it and started pushing it out to their customer base well ahead of other manufacturers.  Right now, OpenFlow support really consists to two modes – ON and OFF.  OFF is pretty easy to imagine.  ON is a bit more complicated.  While a switch can be OpenFlow enabled and still forward normal traffic, the practice has always been to either dedicate the switch to OpenFlow forwarding, in effect turning it into a lab switch, or to enable OpenFlow selectively for a group of ports out of the whole switch, kind of like creating a lab VLAN for testing on a production box.  Brocade’s Hybrid Port OpenFlow model allows you to enable OpenFlow on a port and still allow it to do regular traffic forwarding sans OpenFlow.  That may be the best model for adopters going forward due to one overriding factor – cost.  When you take a switch or a group of ports on a switch and dedicate them for OpenFlow, you are cost the enterprise something.  Every port on the switch costs a certain amount of money.  Every minute an engineer spends working on a crazy lab project incurs a cost.  By enabling the network engineers to turn on OpenFlow at will without disrupting the existing traffic flow, Brocade can reduce the opportunity cost of enabling OpenFlow to almost zero.  If OpenFlow just becomes something that works as soon as you enable it, like IPv6 in Windows 7, you don’t have to spend as much time planning for your end node configuration.  You just build the core and let the end nodes figure out they have new capabilities.  I figure that large Brocade networks will see their OpenFlow adoption numbers skyrocket simply because Hybrid Port mode turns the configuration into Easy Mode.

The last interesting software piece that Brocade showed me is a prime example of the kinds of things that I expect SDN to deliver to us in the future.  Brocade has created an application called the Application Resource Broker (ARB).  It sits above the fray of the lower network layers and monitors indicators of a particular application’s health, such as latency and load.  When one of those indicators hits a specific threshold, ARB kicks in to request more resources from vCenter to balance things out.  If the demand on the application continues to rise beyond the available resources, ARB can dynamically move the application to a public cloud instance with a much deeper pool of resources, a process known as cloudbursting.  All of this can happen automatically without the intervention of IT.  This is one of the things that shows me what SDN can really do.  Software can take care of itself and dynamically move things around when abnormal demand happens.  Intelligent choices about the network environment can be made on solid data.  No guess what about what “might” be happening.  ARB removes doubt and lag in response time to allow for seamless network repair.  Try doing that with a telnet session.

There’s a lot more to the Brocade announcement than just software.  You can check it out at http://www.brocade.com.  You can also follow them on Twitter as @BRCDComm.


Tom’s Take

The future looks interesting at first.  Flying cars, moving sidewalks, and 3D user interfaces are all staples of futuristic science fiction.  The problem for many arises when we need to start taking steps to build those fanciful things.  A healthy dose of pragmatism helps to figure out what we need to do today to make tomorrow happen.  If we root our views of what we want to do with what we can do, then the future becomes that much more achievable.  Even the amazing gadgets we take for granted today have a basis in the real technology of the time they were first created.  By making those incremental steps, we can arrive where we want to be a whole lot sooner with a better understanding of how amazing things really are.

IOS X-Treme!

IOSXtreme

As a nerd, I’m a huge fan of science fiction. One of my favorite shows was Stargate SG-1. Inside the show, there was a joke involving an in-universe TV program called “Wormhole X-Treme” that a writer unintentionally created based on knowledge of the fictional Stargate program. Essentially, it’s a story that’s almost the same as the one we’re watching, with just enough differences to be a totally unique experience. In many ways, that’s how I feel about the new versions of Cisco’s Internetwork Operating System (IOS) that have been coming out in recent months. They may look very similar to IOS. They may behave similarly to IOS. But to mistake them for IOS isn’t right. In this post, I’m going to talk about the three most popular IOS-like variants – IOS XE, IOS XR, and NX-OS.

IOS XE

IOS XE is the most IOS-like of all the new IOS builds that have been released. That’s because the entire point of the IOS XE project was to rebuild IOS to future proof the technology. Right now, the IOS that runs on routers (which will henceforth be called IOS Classic) is a monolithic kernel that runs all of the necessary modules in the same memory space. This means that if something happens to the routing engine or the LED indicator, it can cause the whole IOS kernel to crash if it runs out of memory. That may have been okay years ago but today’s mission critical networks can’t afford to have a rogue process bringing down an entire chassis switch. Cisco’s software engineers set out on a mission to rebuild the IOS CLI on a more robust platform.

IOS XE runs as a system daemon on a “modern Linux platform.” Which one is anyone’s guess. Cisco also abstracted the system functions out of the main kernel and into separate processes. That means that if one of them goes belly up it won’t take the core kernel with it. One of the other benefits of running the kernel as a system daemon is that you can now balance the workload of the processes across multiple processor cores. This was one of the more exciting things to me when I saw IOS XE for the first time. Thanks to the many folks that pointed out to me that the ASR 1000 was the first device to run IOS XE. The Catalyst 4500 (the first switch to get IOS XE) is using a multi core processor to do very interesting things, like the ability to run inline Wireshark on a processor core while still letting IOS have all the processor power it needs. Here’s a video describing that:

Because you can abstract the whole operation of the IOS feature set, you can begin to do things like offer a true virtual router like the CSR 1000. As many people have recently discovered, the CSR 1000 is built on IOS XE and can be booted and operated in a virtualized environment (like VMware Fusion or ESXi). The RAM requirements are fairly high for a desktop virtualization platform (CSR requires 4GB of RAM to run), but the promise is there for those that don’t want to keep using GNS3/Dynamips or Cisco’s IOU to emulate IOS-like features. IOS XE is the future of IOS development. It won’t be long until the next generation of supervisor engines and devices will be using it exclusively instead of relying on IOS Classic.

IOS XR

In keeping with the sci-fi theme of this post, IOS XR is what the Mirror Universe version of IOS would look like. Much like IOS XE, IOS XR does away with the monolithic kernel and shared memory space of IOS Classic. XR uses an OS from QNX to serve as the base for the IOS functions. XR also segments the ancillary process in IOS into separate memory spaces to prevent system crashes from an errant bug. XR is aimed at the larger service provider platforms like the ASR 9000 and CRS series of routers. You can see that in the way that XR can allow multiple routing protocol processes to be executed at the same time in different memory spaces. That’s a big key to the service provider.

What makes IOS XR so different from IOS Classic? That lies in the configuration method. While the CLI may resemble the IOS that you’re used to, the change methodology is totally foreign to Cisco people. Instead of making live config changes on a live system, the running configuration is forked into a separate memory space. Once you have created all the changes that you need to make, you have to perform a sanity check on the config before it can be moved into live production. That keeps you from screwing something up accidentally. Once you have performed a sanity check, you have to explicitly apply the configuration via a commit command. In the event that the config you applied to the router does indeed contain errors that weren’t caught by the sanity checker (like the wrong IP), you can issue a command to revert to a previous working config in a process known as rollback. All of the previous configuration sets are retained in NVRAM and remain available for reversion.

If you’re keeping track at home, this sounds an awful lot like Junos. Hence my Mirror Universe analogy. IOS XR is aimed at service providers, which is a market dominated by Juniper. SPs have gotten very used to the sanity checking and rollback capabilities provided by Junos. Cisco decided to offer those features in an SP-specific IOS package. There are many that want to see IOS XR ported from the ASR/CSR lines down into more common SP platforms. Only time will tell if that will happen. Jeff Fry has an excellent series of posts on IOS XR that I highly recommend if you want to learn more about the specifics of configuration on that platform.

NX-OS

NX-OS is the odd man out from the IOS family. It originally started life as Cisco’s SAN-OS, which was responsible for running the MDS line of fibre channel switches. Once Cisco started developing the Nexus switching platform, they decided to use SAN-OS as the basis for the operating system, as it already contained much of the code that would be needed to allow networking and storage protocols to interoperate on the device, a necessity for a converged data center switch. Eventually, the new OS became known as NX-OS.

NX-OS looks similar to the IOS Classic interface that most engineers have become accustomed to. However, the underlying OS is very different from what you’re used to. First off, not every feature of classic IOS is available on demand. Yes, a lot of the more esoteric feature sets (like the DHCP server) are just plain unavailable. But even the feature sets that are listed as available in the OS may not be in the actual running code. You need to active each of these via use of the feature keyword when you want to enable them. This “opt in” methodology ensures that the running code only contains essential modules as well as the features you want. That should make the security people happy from an exploit perspective, as it lowers the available attack surface of your OS.

Another unique feature of NX-OS is the interface naming convention. In IOS Classic, each interface is named via the speed. You can have Ethernet, FastEthernet, GigabitEthernet, TenGigabit, and even FortyGigabit interfaces. In NX-OS, you have one – Ethernet. NX-OS treats all interfaces as Ethernet regardless of the underlying speed. That’s great for a modular switch because it allows you to keep the same configuration no matter which line cards are running in the device. It also allows you to easily port the configuration to a newer device, say from Nexus 5500 to Nexus 6000, without needed to do a find/replace operation on the config and risk changing a line you weren’t supposed to. Besides, most of the time the engineer doesn’t care about whether an interface is gigabit or ten gigabit. They just want to program the second port on the third line card.


Tom’s Take

No software program can survive without updates. Especially if it is an operating system. The hardware designed to run version 1.0 is never the same as the hardware that version 5.0 or even 10.0 utilizes. Everything evolves to become more efficient and useful. Think of it like seasons of sci-fi shows. Every season tells a story. There may be some similarities, but people overall want the consistency of the characters they’ve come to love coupled with new stories and opportunities to increase character development. Network operating systems like IOS are no different. Engineers want the IOS-like interface but they also want separated control planes, robust sanity checking, and modularized feature insertion. Much like the writers of sci-fi, Cisco will continue to provide new features and functionality while still retaining the things to which we’ve grown accustomed. However, if Cisco ever comes up with a hare-brained idea like the Ori, I can promise there’s no way I’ll ever run IOS-Origin.

Brocade Defined Networking

logo-brocade

Brocade stepped up to the plate once again to present to the assembled delegates at Network Field Day 5.  I’ve been constantly impressed with what they bring each time they come to the party.  Sometimes it’s a fun demo.  Other times its a great discussion around OpenFlow.  With two hours to spend, I wanted to see how Brocade would steer this conversation.  I could guarantee that it would involve elements of software defined networking (SDN), as Brocade has quietly been assembling a platoon on SDN-focused luminaries.  What I came away with surprised even me.

Mike Schiff takes up the reigns from Lisa Caywood for the title of Mercifully Short Introductions.  I’m glad that Brocade assumes that we just need a short overview for both ourselves and the people watching online.  At this point, if you are unsure of who Brocade is you won’t get a feel for it in eight short minutes.

Curt Beckman started off with fifteen minutes of discussion about where the Open Networking Foundation (ONF) is concentrating on development.  Because Curt is the chairman of the ONF, we kind of unloaded on him a bit about how the ONF should really be called the “Open-to-those-with-$30,000-to-spare Networking Foundation”.  That barrier to entry really makes it difficult for non-vendors to have any say in the matters of OpenFlow.  Indeed, the entry fee was put in place specifically to deter those not materially interested in creating OpenFlow based products from discussing the protocol.  Instead, you have the same incumbent vendors that make non-OpenFlow devices today steering the future of the standard.  Unlike the IETF,  you can’t just sign up for the mailing list or show up to the meetings and say your peace.  You have to have buy in, both literally and figuratively.  I proposed the hare-brained idea of creating a Kickstarter project to raise the necessary $30,000 for the purpose of putting a representative of “the people” in the ONF.  In discussions that I’ve had before with IETF folks they all told me you tend to see the same thing over and over again.  Real people don’t sit on committees.  The IETF is full of academics that argue of the purity of an OAM design and have never actually implemented something like that in reality.  Conversely, the ONF is now filled with deep pocketed people that are more concerned with how they can use OpenFlow to sell a few more switches rather than now best to implement the protocol in reality.  If you’d like to donate to an ONF Kickstarter project, just let me know and I’ll fire it up.  Be warned – I’m planning on putting Greg Ferro (@etherealmind) and Brent Salisbury (@networkstatic) on the board.  I figure that should solve all my OpenFlow problems.

The long presentation of this hour was all about OpenFlow and hybrid switching.  I’ve seen some of the aspects of this in my day job.  One of the ISPs in my area is trying to bring a 100G circuit into the state for Internet2 SDN-enabled links.  The demo that I saw in their office was pretty spiffy.  You could slice off any section of the network and automatically build a path between two nodes with a few simple clicks.  Brocade expanded my horizons of where these super fast circuits were being deployed with discussions of QUILT and GENI as well as talking about projects across the ocean in Australia and Japan.  I also loved the discussions around “phasing” SDN into your existing network.  Brocade realizes that no one is going to drop everything they currently have and put up an full SDN network all at once.  Instead, most people are going to put in a few SDN-enabled devices and move some flows to them at first both as a test and as a way to begin new architecture.  Just like remodeling a house, you have to start somewhere and shore up a few areas before you can really being to change the way everything is laid out.  That is where the network will eventually lead to being fully software defined down the road.  Just realize that it will take time to get there.

Next up was a short update from Vyatta.  They couldn’t really go into a lot of detail about what they were doing, as they were still busy getting digested by Brocade after being acquired.  I don’t have a lot to say about them specifically, but there is one thing I thought about as I mulled over their presentation.  I’m not sure how much Vyatta plays into the greater SDN story when you think about things like full API programmability, orchestration, and even OpenFlow.  Rather than being SDN, I think products like Vyatta and even Cisco’s Nexus 1000v should instead be called NDS – Networking Done (by) Software.  If you’re doing Network Function Virtualization (NFV), how much of that is really software definition versus doing your old stuff in a new way?  I’ve got some more, deeper thoughts on this subject down the road.  I just wanted to put something out there about making sure that what you’re doing really is SDN instead of NDS, which is a really difficult moving target to hit because the definition of what SDN really does changes from day to day.

Up next is David Meyer talking about Macro Trends in Networking.  Ho-ly crap.  This is by far my favorite video from NFD5.  I can say that with comfort because I’ve watched it five times already.  David Meyer is a lot like Victor Shtrom from Ruckus at WFD2.  He broke my brain after this presentation.  He’s just a guy with some ideas that he wants to talk about.  Except those ideas are radical and cut right to the core of things going on in the industry today.  Let me try to form some thoughts out of the video above, which I highly recommend you watch in its entirety with no distractions.  Also, have a pen and paper handy – it helps.

David is talking about networks from a systems analysis perspective.  As we add controls and rules and interaction to a fragile system, we increase the robustness of that system.  Past a certain point, though, all those extra features end up harming the system.  While we can cut down on rules and oversight, ultimately we can’t create a truly robust system until we can remove a large portion of the human element.  That’s what SDN is trying to do.  By allowing humans to interact with the rules and not the network itself you can increase the survivability of the system.  When we talk about complex systems, we really talk about increasing their robustness while at the same time adding features and flexibility.  That’s where things like SDN come into the discussion in the networking system.  SDN allows us to constrain the fragility of a system by creating a rigid framework to reduce the complexity.  That’s the “bow tie” diagram about halfway in.  We have lots of rules and very little interaction from agents that can cause fragility.  When the outputs come out of SDN, the are flexible and unconstrained again but very unlikely to contribute to fragility in the system.  That’s just one of the things I took away from this presentation.  There are several more that I’d love to discuss down the road once I’ve finished cooking them in my brain.  For now, just know that I plan on watching this presentation several more times in the coming weeks.  There’s so much good stuff in such a short time frame.  I wish I could have two hours with David Meyer to just chat about all this crazy goodness.

If you’d like to learn more about Brocade, you can check out their website at http://www.brocade.com.  You can also follow them on Twitter as @BRCDcomm


Tom’s Take

Brocade gets it.  They’ve consistently been running in the front of the pack in the whole SDN race.  They understand things like OpenFlow.  They see where the applications are and how to implement them in their products.  They engage with the builders of what will eventually become the new SDN world.  The discussions that we have with Curt Beckman and David Meyer show that there are some deep thinkers that are genuinely invested in the future of SDN and not just looking to productize it.  Mark my words – Brocade is poised to leverage their prowess in SDN to move up the ladder when it comes to market share in the networking world.  I’m not saying this lightly either.  There’s an adage attributed to Wayne Gretskey – “Don’t skate where the puck is.  Skate where the puck is going.”  I think Brocade is one of the few networking companies that’s figured out where the puck is going.

Tech Field Day Disclaimer

Brocade was a sponsor of Network Field Day 5.  As such, they were responsible for covering a portion of my travel and lodging expenses while attending Network Field Day 5.  In addition, Brocade provided a USB drive of marketing material and two notepads styled after RFC 2460.  At no time did they ask for, nor where they promised any kind of consideration in the writing of this review.  The opinions and analysis provided within are my own and any errors or omissions are mine and mine alone.

Cisco Borderless Idol

Cisco Logo

Day one of Network Field Day 5 (NFD5) included presentations from the Cisco Borderless team. You probably remember their “speed dating” approach at NFD4 which gave us a wealth of information in 15 minute snippets. The only drawback to that lineup is when you find a product or a technology that interests you there really isn’t any time to quiz the presenter before they are ushered off stage. Someone must have listened when I said that before, because this time they brought us 20 minute segments – 10 minutes of presentation, 10 minutes of demo. With the switching team, we even got to vote on our favorite to bring the back for the next round (hence the title of the post). More on that in a bit.

6500 Quad Supervisor Redundancy

First up on the block was the Catalyst 6500 team. I swear this switch is the Clint Howard of networking, because I see it everywhere. The team wanted to tell us about a new feature available in the ((verify code release)) code on the Supervisor 2T (Sup2T). Previously, the supervisor was capable of performing a couple of very unique functions. The first of these was Stateful Switch Over (SSO). During SSO, the redundant supervisor in the chassis can pick up where the primary left off in the event of a failure. All of the traffic sessions can keep on trucking even if the active sup module is rebooting. This gives the switch a tremendous uptime, as well as allowing for things like hitless upgrades in production. The other existing feature of the Sup2T is Virtual Switching System (VSS). VSS allows two Sup2Ts to appear as one giant switch. This is helpful for applications where you don’t want to trust your traffic to just one chassis. VSS allows for two different chassis to terminate Multi-Chassis EtherChannel (MLAG) connections so that distribution layer switches don’t have a single point of failure. Traffic looks like it’s flowing to one switch when in actuality it may be flowing to one or the other. In the event that a Supervisor goes down, the other one can keep forwarding traffic.

Enter the Quad Sup SSO ability. Now, instead of having an RPR-only failover on the members of a VSS cluster, you can setup the redundant Sup2T modules to be ready and waiting in the event of a failure. This is great because you can lose up to three Sup2Ts at once and still keep forwarding while they reboot or get replaced. Granted, anything that can take out 3 Sup2Ts at once is probably going to take down the fourth (like power failure or power surge), but it’s still nice to know that you have a fair amount of redundancy now. This only works on the Sup2T, so you can’t get this if you are still running the older Sup720. You also need to make sure that your linecards support the newer Distributed Forwarding Card 3 (DFC3), which means you aren’t going to want to do this with anything less than a 6700-series line card. In fact, you really want to be using the 6800 series or better just to be on the safe side. As Josh O’brien (@joshobrien77) commented, this is a great feature to have. But it should have been there already. I know that there are a lot of technical reasons why this wasn’t available earlier, and I’m sure the increase fabric speeds in the Sup2T, not to mention the increased capability of the DFC3, are the necessary component for the solution. Still, I think this is something that probably should have shipped in the Sup2T on the first day. I suppose that given the long road the Sup2T took to get to us that “better late than never” is applicable here.

UCS-E

Next up was the Cisco UCS-E series server for the ISR G2 platform. This was something that we saw at NFD4 as well. The demo was a bit different this time, but for the most part this is similar info to what we saw previously.


Catalyst 3850 Unified Access Switch

The Catalyst 3800 is Cisco’s new entry into the fixed-configuration switch arena. They are touting this a “Unified Access” solution for clients. That’s because the 3850 is capable of terminating up to 50 access points (APs) per stack of four. This think can basically function as a wiring closet wireless controller. That’s because it’s using the new IOS wireless controller functionality that’s also featured in the new 5760 controller. This gets away from the old Airespace-like CLI that was so prominent on the 2100, 2500, 4400, and 5500 series controllers. The 3850, which is based on the 3750X, also sports a new 480Gbps Stackwise connector, appropriately called Stackwise480. This means that a stack of 3850s can move some serious bits. All that power does come at a cost – Stackwise480 isn’t backwards compatible with the older Stackwise v1 and v2 from the 3750 line. This is only an issue if you are trying to deploy 3850s into existing 3750X stacks, because Cisco has announced the End of Sale (EOS) and End of Life (EOL) information for those older 3750s. I’m sure the idea is that when you go to rip them out, you’ll be more than happy to replace them with 3850s.

The 3850 wireless setup is a bit different from the old 3750 Access Controller that had a 4400 controller bolted on to it. The 3850 uses Cisco’s IOS-XE model of virtualizing IOS into a sort of VM state that can run on one core of a dual-core processor, leaving the second core available to do other things. Previously at NFD4, we’d seen the Catalyst 4500 team using that other processor core for doing inline Wireshark captures. Here, the 3850 team is using it to run the wireless controller. That’s a pretty awesome idea when you think about it. Since I no longer have to worry about IOS taking up all my processor and I know that I have another one to use, I can start thinking about some interesting ideas.

The 3850 does have a couple of drawbacks. Aside from the above Stackwise limitations, you have to terminate the APs on the 3850 stack itself. Unlike the CAPWAP connections that tunnel all the way back to the Airespace-style controllers, the 3850 needs to have the APs directly connected in order to decapsulate the tunnel. That does provide for some interesting QoS implications and applications, but it doesn’t provide much flexibility from a wiring standpoint. I think the primary use case is to have one 3850 switch (or stack) per wiring closet, which would be supported by the current 50 AP limitation. the othe drawback is that the 3850 is currently limited to a stack of four switches, as opposed to the increased six switch limit on the 3750X. Aside from that, it’s a switch that you probably want to take a look at in your wiring closets now. You can buy it with an IP Base license today and then add on the AP licenses down the road as you want to bring them online. You can even use the 3850s to terminate CAPWAP connections and manage the APs from a central controller without adding the AP license.

Here is the deep dive video that covers a lot of what Cisco is trying to do from a unified wired and wireless access policy standpoint. Also, keep an eye out for the cute Unifed Access video in the middle.

Private Data Center Mobility

I found it interesting this this demo was in the Borderless section and not the Data Center presentation. This presentation dives into the world of Overlay Transport Virtualization (OTV). Think of OTV like an extra layer of 802.1 q-in-q tunneling with some IS-IS routing mixed in. OTV is Cisco’s answer to extending the layer 2 boundary between data centers to allow VMs to be moved to other sites without breaking their networking. Layer 2 everywhere isn’t the most optimal solution, but it’s the best thing we’ve got to work with the current state of VM networking (until Nicira figures out what they’re going to do).

We loved this session so much that we asked Mostafa to come back and talk about it more in depth.

The most exciting part of this deep dive to me was the introduction of LISP. To be honest, I haven’t really been able to wrap my head around LISP the first couple of times that I saw it. Now, thanks to the Borderless team and Omar Sultan (@omarsultan), I’m going to dig into a lot more in the coming months. I think there are some very interesting issues that LISP can solve, including my IPv6 Gordian Knot.


Tom’s Take

I have to say that I liked Cisco’s approach to the presentations this time.  Giving us discussion time along with a demo allowed us to understand things before we saw them in action.  The extra five minutes did help quite a bit, as it felt like the presenters weren’t as rushed this time.  The “Borderless Idol” style of voting for a presentation to get more info out of was brilliant.  We got to hear about something we wanted to go into depth about, and I even learned something that I plan on blogging about later down the line.  Sure, there was a bit of repetition in a couple of areas, most notably UCS-E, but I can understand how those product managers have invested time and effort into their wares and want to give them as much exposure as possible.  Borderless hits all over the spectrum, so keeping the discussion focused in a specific area can be difficult.  Overall, I would say that Cisco did a good job, even without Ryan Secrest hosting.

Tech Field Day Disclaimer

Cisco was a sponsor of Network Field Day 5.  As such, they were responsible for covering a portion of my travel and lodging expenses while attending Network Field Day 5.  In addition, Cisco provided me with a breakfast and lunch at their offices.  They also provided a Moleskine notebook, a t-shirt, and a flashlight toy.  At no time did they ask for, nor where they promised any kind of consideration in the writing of this review.  The opinions and analysis provided within are my own and any errors or omissions are mine and mine alone.