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This is part 15 of my Learning NSX blog series, in which I will spend some time diving a bit deeper into some of the components involved in the logical routing process I described in part 14. Specifically, I’ll be taking a deeper look at gateway appliances, gateway services, and logical routers, and the relationships among these various components.

If you haven’t read any of the prior posts in this series, it would be ideal to read all of them before continuing; you can find links on my Learning NVP/NSX page. In particular, I’d suggest reading part 6 (on adding a gateway appliance), part 9 (on adding a gateway service), and part 14 (on logical routing and logical routers).

Just for the sake of completeness and to reinforce what was introduced in those posts I referenced, let’s start with some terminology:

  • Gateway (or gateway appliance): When I use the terms gateway or gateway appliance, I’m referring to the NSX software gateway that acts as the “on-ramp/off-ramp” to and from logical networks. What makes this confusing is that we also use the term “gateway” (in particular, “IP gateway” or “default gateway”) to refer to a Layer 3 router that acts as the next hop for a aystem. I’ll do my best to make sure that I’m clearly distinguishing between these ambiguous uses.
  • Gateway service: A gateway service is a logical construct within NSX that allows you to group together multiple gateway appliances. For example, in an L2 gateway service, you can combine two gateway appliances so that you have redundancy in providing L2 bridging functionality between a logical network and a physical network. In an L3 gateway service, you can combine up to 10 gateway appliances together for redundancy and scale-out performance.
  • Logical router: As you might recall from part 14, a logical router is a logical construct within NSX that provides Layer 3 routing functionality, typically (but not always) on a per-tenant basis.

I have a few more terms I’ll introduce in this post, but that should be enough for now.

This diagram contains the bulk of what I’d like to discuss in this post—the relationship between gateway services, gateway appliances, and logical routers:

As I walk you through the details of this diagram, hopefully I’ll clarify the relationships between these components.

  • In this example, there are four gateway appliances combined into a single Layer 3 gateway service. As illustrated in the diagram, gateway services can contain more than one gateway appliance (the minimum recommended is two, for reasons to be explained shortly). Gateway services may be either Layer 2 (bridging/switching) or Layer 3 (routing), but not both.
  • A gateway appliance may be a member of only one gateway service at a time; therefore, a gateway appliance is either L2 or L3, but not both.
  • When adding a gateway appliance to a gateway service, the administrator or operator has the ability to specify a failure zone ID. The idea behind the failure zone ID is to help model fault domains within a single gateway service. For example, if GW Appliance 1 is in a different fault domain—say, a different rack—then the administrator or operator could assign a different failure zone ID to GW Appliance 1, indicating that GW Appliance 1 is in a different fault domain. The significance of this functionality will be made clear in a moment.
  • Note that gateway services, gateway appliances, and failure zone IDs are not visible to tenants. Further, the configuration or management of these entities is handled through NSX (via API or NSX Manager), and isn’t tenant-specific. The CMP—OpenStack, for example—doesn’t get involved here.
  • The example diagram shows four different logical routers spread across three tenants. Each of these logical routers acts as an IP gateway (default gateway/default route) for the associated (or connected) logical network(s). Thus, a logical router is visible to a tenant.
  • Creating, managing, and configuring logical routers is handled by the CMP. With OpenStack, for example, you’d use the OpenStack Dashboard or the Neutron command-line client.
  • For redundancy, you’ll note that each logical router is instantiated on 2 different gateway appliances within the gateway service (hence why a minimum of 2 gateway appliances within a gateway service is recommended). This is completely invisible to the tenant and is handled automatically by NSX. If failure zone IDs—indicating different fault domains—are configured on the gateway appliances, then NSX will instantiate the logical router on gateway appliances in different failure zones. This is an attempt to minimize downtime by spreading the logical router across fault domains.

So far, everything I’ve shared with you has been true for centralized logical routers. For distributed logical routers, things are only slightly different. Distributed logical routers are normally instantiated on the hypervisors; a gateway service and its associated gateway appliances only gets involved when you set the uplink for the distributed logical router (using the “Set Gateway” button in OpenStack Dashboard, for example). If you never set an uplink for the logical router, it will remain instantiated only on the hypervisors, and not on the gateway service/gateway appliances.

I hope this information helps in understanding the routing aspects of VMware NSX. Feel free to post any questions, clarifications, or thoughts in the comments below. Any input on other topics you’d like to see in the Learning NSX blog series are welcome as well!

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Welcome to part 14 of the Learning NSX blog series, in which I discuss the ability for VMware NSX to do Layer 3 routing in logical networks. This post will also include a look at a very cool feature within VMware NSX known as distributed logical routing. This post will take a closer look at distributed logical routing within the context of an OpenStack environment that’s been integrated with VMware NSX. (Although NSX isn’t necessarily tied to OpenStack, I’ll assume you’re using OpenStack just to simplify the discussion.)

If you’re new to this series, you can find links to all the articles on my Learning NVP/NSX page. Ideally, I’d recommend you read all the articles, but if you’re just interested in some of the high-level concepts you probably don’t need to do that. For those interested in the deep technical details, I’d suggest catching up on the series before proceeding.

Overview of Logical Routing

One of the features of VMware NSX that can be useful, depending on customer requirements, is the ability to create complex network topologies. For example, creating a multi-tier network topology like the one shown below is easily accomplished via VMware NSX:

Sample network topology

Note that this topology has two tenant-specific routing entities—these are logical routers. A logical router is an abstraction created and maintained by VMware NSX on behalf of your cloud management platform (like OpenStack, which I’ll assume you’re using here). These logical entities perform the routing process just like a physical router would (forwarding traffic based on a routing table, changing the source and destination MAC address, maintaining an ARP cache of MAC addresses, decrementing the TTL, etc.). Of course, they are not exactly the same as physical routers; you can’t, for example, connect two logical routers directly to each other.

Logical routers also act as the logical boundary between one or more logical networks and an external network. Logical routers can be connected to multiple logical networks (each logical network with its own logical router interface), but can only be connected to a single external network. Thus, you can’t use a logical router as a transit path between two external networks (two VLANs, for example).

Now that you have a good understanding of logical routing, let’s take a closer look at the various components inside VMware NSX.

Components of Logical Routing

The components are pretty straightforward. In addition to the logical router abstraction that I’ve discussed already, you also have logical router ports (naturally, these are the ports on a logical router that connect it to a logical network or an external network), network address translation (NAT) rules (for handling address translation tasks), and a routing table (for…well, routing).

You can see all of these components in NSX Manager. Once you’re logged into NSX Manager, select Network Components > Logical Layer > Logical Routers, then click on a specific logical router from the list. This will display the screen shown below (click the image for a larger version):

Logical router detail in NSX Manager

A few things to note here:

  • You’ll note that the logical router has a port whose attachment is listed as “L3GW”. This denotes an attachment to a Layer 3 Gateway Service, an entity I described in part 9 of the series. This Layer 3 Gateway Service is itself comprised of two NSX gateway appliances; part 6 in the series discussed how to add a gateway appliance to your installation. The relationship between logical router, Layer 3 Gateway Service, and gateway appliance can be confusing for some; I plan to discuss that in more detail in the next post.
  • This particular logical router is not configured as a distributed logical router. This means that the actual routing function resides on a Layer 3 Gateway Service. The routing functionality is instantiated in a highly available configuration on two different gateway appliances within the Layer 3 Gateway Service.
  • NAT Synchronization is set to on; this refers to keeping NAT state synchronized between the active and standby routing functions instantiated on the gateway appliances.
  • As noted under Replication Mode, this router uses an NSX service node (refer to part 10 for more details on service nodes) for packet replication/BUM traffic.
  • You might notice that one of the logical router ports is assigned the IP address 169.254.169.253 (and you’ll also note a corresponding “no NAT” rule and routing table entries for that same network). Astute readers recognize this as the network for Automatic Private IP Addressing (APIPA), also known as IPv4 Link-Local Addresses per RFC 3927. This exists to support an OpenStack-specific feature known as the metadata service, and is created automatically by OpenStack. (I’ll talk more about OpenStack later in this post.)

All of these components and settings are accessible via the NSX API, and since NSX Manager is completely an API client (it merely consumes NSX APIs and does not provide standalone functionality outside of some logging features), you could create, modify, and delete any of the logical routing components directly within NSX Manager. (Or, if you were so inclined, you could make the API calls yourself to do these tasks.) Typically, though, these tasks would be handled via integration between NSX and your cloud management platform, like OpenStack.

One key component of NSX’s logical routing functionality that you can’t see in NSX Manager is how the routing is actually implemented in the data plane. As with most features in NSX, the actual data plane implementation is handled via Open vSwitch (OVS) and a set of flow rules pushed down by the NSX controllers. These flow rules control the flow of traffic within and between logical networks (logical switches in NSX). You can see some of the flow rules in OVS using the ovs-dpctl dump-flows command, which will produce output something like what’s shown in this screenshot (note that the addresses are highlighted because I used grep to show only the flows matching a certain IP address):

List of flows in OVS

(Click the image above for a larger version.)

These flow rules include actions like re-writing source and destination MAC addresses and decrementing the TTL, both tasks carried out by “normal” routers when routing traffic between networks. These flow rules also provide some insight into the differences between a logical router and a distributed logical router. While both are logical entities, the way in which the data plane is implemented is different for each:

  • For a logical router, the flow rules will direct traffic to the appropriate gateway appliance in the Layer 3 Gateway Service. The logical router is actually instantiated on a gateway appliance, so all routed traffic must go to the logical router, get “routed” (routing table consulted, source and destination MAC re-written, TTL decremented, NAT rules applied, etc.), then get sent on to the final destination (which might be a VM on a hypervisor in NSX or might be a physical network outside of NSX).
  • For a distributed logical router, the flow rules will direct traffic either to the appropriate gateway appliance in the Layer 3 Gateway Service or to the destination hypervisor directly. Why the “either/or”? If the traffic is north/south traffic—that is, traffic being routed out of a logical network onto the physical network—then it must go to the gateway appliance (which, as I have mentioned before, is where traffic is unencapsulated and placed onto the physical network). However, if the traffic is east/west traffic—traffic that is moving from one server on a logical network to another server on a logical network—then the traffic is “routed” directly on the source hypervisor and then sent across an encapsulated connection to the hypervisor where the destination VM resides.

In both cases, there is only one logical router. For a non-distributed logical router, the data plane is instantiated on a gateway appliance only. For a distributed logical router, the data plane is instantiated both on the local hypervisors as well as on a gateway appliance. (This is assuming you’ve set an uplink on the logical router, meaning you have a north/south connection. If you haven’t set an uplink, then the routing functionality is instantiated on the hypervisors only.)

This should provide a good overview of how logical routing is implemented in VMware NSX, but there’s one more aspect I want to cover: logical routers in OpenStack with NSX.

Logical Routers in OpenStack

As you work with OpenStack Networking—Neutron, as it’s commonly called—you’ll find that the abstractions Neutron uses map really well to the abstractions that NSX uses. So, to create a logical router in NSX, you just create a logical router in OpenStack. Attaching an OpenStack logical router to a logical network tells NSX to create the logical switch port, create the logical router port, and connect the two ports together.

In OpenStack, there are a number of different ways to create a logical router:

  • OpenStack Dashboard (Horizon)
  • Command-line interface (CLI)
  • OpenStack Orchestration (Heat) template
  • API calls directly

When using the web-based Dashboard user interface, you can only create centralized logical routers, not distributed logical routers. The Dashboard UI also doesn’t provide any way of knowing if a logical router is distributed or not; for that, you’ll need the CLI (the command is provided shortly).

On a system with the neutron CLI client installed, you can create a logical router like this:

neutron router-create <router name>

This creates a centralized logical router. If you want to create a distributed logical router, it’s as simple as this:

neutron router-create <router name> -\-distributed True

The neutron router-show command will return output about the specified logical router; that output will tell you if it is a distributed logical router.

The neutron CLI client also offers commands to update a logical router’s routing table (to add or remove static routes, for example), or to connect a logical router to an external network (to set an uplink, in other words).

If you want to create a logical router as part of a stack created via OpenStack Orchestration (Heat), you could use this YAML snippet in a HOT-formatted template to create a distributed logical router (click here if you can’t see the code block below):

OpenStack Heat also offers resource types for setting the router’s external gateway and creating router interfaces (logical router ports). If you aren’t familiar with OpenStack Heat, you might find this introduction useful.

That wraps up this post on logical routing with VMware NSX. As always, I welcome your courteous feedback, so feel free to speak up in the comments below. In the next post, I’ll spend a bit of time discussing logical routers, gateway servies, and gateway appliances. See you next time!

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Welcome to Technology Short Take #42, another installation in my ongoing series of irregularly published collections of news, items, thoughts, rants, raves, and tidbits from around the Internet, with a focus on data center-related technologies. Here’s hoping you find something useful!

Networking

  • Anthony Burke’s series on VMware NSX continues with part 5.
  • Aaron Rosen, a Neutron contributor, recently published a post about a Neutron extension called Allowed-Address-Pairs and how you can use it to create high availability instances using VRRP (via keepalived). Very cool stuff, in my opinion.
  • Bob McCouch has a post over at Network Computing (where I’ve recently started blogging as well—see my first post) discussing his view on how software-defined networking (SDN) will trickle down to small and mid-sized businesses. He makes comparisons among server virtualization, 10 Gigabit Ethernet, and SDN, and feels that in order for SDN to really hit this market it needs to be “not a user-facing feature, but rather a means to an end” (his words). I tend to agree—focusing on SDN is focusing on the mechanism, rather than focusing on the problems the mechanism can address.
  • Want or need to use multiple external networks in your OpenStack deployment? Lars Kellogg-Stedman shows you how in this post on multiple external networks with a single L3 agent.

Servers/Hardware

  • There was some noise this past week about Cisco UCS moving into the top x86 blade server spot for North America in Q1 2014. Kevin Houston takes a moment to explore some ideas why Cisco was so successful in this post. I agree that Cisco had some innovative ideas in UCS—integrated management and server profiles come to mind—but my biggest beef with UCS right now is that it is still primarily a north/south (server-to-client) architecture in a world where east/west (server-to-server) traffic is becoming increasingly critical. Can UCS hold on in the face of a fundamental shift like that? I don’t know.

Security

  • Need to scramble some data on a block device? Check out this command. (I love the commandlinefu.com site. It reminds me that I still have so much yet to learn.)

Cloud Computing/Cloud Management

  • Want to play around with OpenDaylight and OpenStack? Brent Salisbury has a write-up on how to OpenStack Icehouse (via DevStack) together with OpenDaylight.
  • Puppet Labs has released a module that allows users to programmatically (via Puppet) provision and configure Google Compute Platform (GCP) instances. More details are available in the Puppet Labs blog post.
  • I love how developers come up with these themes around certain projects. Case in point: “Heat” is the name of the project for orchestrating resources in OpenStack, HOT is the name for the format of Heat templates, and Flame is the name of a new project to automatically generate Heat templates.

Operating Systems/Applications

  • I can’t imagine that anyone has been immune to the onslaught of information on Docker, but here’s an article that might be helpful if you’re still looking for a quick and practical introduction.
  • Many of you are probably familiar with Razor, the project that former co-workers Nick Weaver and Tom McSweeney created when they were at EMC. Tom has since moved on to CSC (via the vCHS team at VMware) and has launched a “next-generation” version of Razor called Hanlon. Read more about Hanlon and why this is a new/separate project in Tom’s blog post here.
  • Looking for a bit of clarity around CoreOS and Project Atomic? I found this post by Major Hayden to be extremely helpful and informative. Both of these projects are on my radar, though I’ll probably focus on CoreOS first as the (currently) more mature solution.
  • Linux Journal has a nice multi-page write-up on Docker containers that might be useful if you are still looking to understand Docker’s basic building blocks.
  • I really enjoyed Donnie Berkholz’ piece on microservices and the migrating Unix philosophy. It was a great view into how composability can (and does) shift over time. Good stuff, I highly recommend reading it.
  • cURL is an incredibly useful utility, especially in today’s age of HTTP-based REST API. Here’s a list of 9 uses for cURL that are worth knowing. This article on testing REST APIs with cURL is handy, too.
  • And for something entirely different…I know that folks love to beat up AppleScript, but it’s cross-application tasks like this that make it useful.

Storage

  • Someone recently brought the open source Open vStorage project to my attention. Open vStorage compares itself to VMware VSAN, but supporting multiple storage backends and supporting multiple hypervisors. Like a lot of other solutions, it’s implemented as a VM that presents NFS back to the hypervisors. If anyone out there has used it, I’d love to hear your feedback.
  • Erik Smith at EMC has published a series of articles on “virtual storage networks.” There’s some interesting content there—I haven’t finished reading all of the posts yet, as I want to be sure to take the time to digest them properly. If you’re interested, I suggest starting out with his introductory post (which, strangely enough, wasn’t the first post in the series), then moving on to part 1, part 2, and part 3.

Virtualization

  • Did you happen to see this write-up on migrating a VMware Fusion VM to VMware’s vCloud Hybrid Service? For now—I believe there are game-changing technologies out there that will alter this landscape—one of the very tangible benefits of vCHS is its strong interoperability with your existing vSphere (and Fusion!) workloads.
  • Need a listing of the IP addresses in use by the VMs on a given Hyper-V host? Ben Armstrong shares a bit of PowerShell code that produces just such a listing. As Ben points out, this can be pretty handy when you’re trying to track down a particular VM.
  • vCenter Log Insight 2.0 was recently announced; Vladan Seget has a decent write-up. I’m thinking of putting this into my home lab soon for gathering event information from VMware NSX, OpenStack, and the underlying hypervisors. I just need more than 24 hours in a day…
  • William Lam has an article on lldpnetmap, a little-known utility for mapping ESXi interfaces to physical switches. As the name implies, this relies on LLDP, so switches that don’t support LLDP or that don’t have LLDP enabled won’t work correctly. Still, a useful utility to have in your toolbox.
  • Technology previews of the next versions of Fusion (Fusion 7) and Workstation (Workstation 11) are available; see Eric Sloof’s articles (here and here for Fusion and Workstation, respectively) for more details.
  • vSphere 4 (and associated pieces) are no longer under general support. Sad face, but time stops for no man (or product).
  • Having some problems with VMware Fusion’s networking? Cody Bunch channels his inner Chuck Norris to kick VMware Fusion networking in the teeth.
  • Want to preview OS X Yosemite? Check out William Lam’s guide to using Fusion or vSphere to preview the new OS X beta release.

I’d better wrap this up now, or it’s going to turn into one of Chad’s posts. (Just kidding, Chad!) Thanks for taking the time to read this far!

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Welcome to Technology Short Take #41, the latest in my series of random thoughts, articles, and links from around the Internet. Here’s hoping you find something useful!

Networking

  • Network Functions Virtualization (NFV) is a networking topic that is starting to get more and more attention (some may equate “attention” with “hype”; I’ll allow you to draw your own conclusion there). In any case, I liked how this article really hit upon what I personally feel is something many people are overlooking in NFV. Many vendors are simply rushing to provide virtualized versions of their solution without addressing the orchestration and automation side of the house. I’m looking forward to part 2 on this topic, in which the author plans to share more technical details.
  • Rob Sherwood, CTO of Big Switch, recently published a reasonably in-depth look at “modern OpenFlow” implementations and how they can leverage multiple tables in hardware. Some good information in here, especially on OpenFlow basics (good for those of you who aren’t familiar with OpenFlow).
  • Connecting Docker containers to Open vSwitch is one thing, but what about using Docker containers to run Open vSwitch in userspace? Read this.
  • Ivan knocks centralized SDN control planes in this post. It sounds like Ivan favors scale-out architectures, not scale-up architectures (which are typically what is seen in centralized control plane deployments).
  • Looking for more VMware NSX content? Anthony Burke has started a new series focusing on VMware NSX in pure vSphere environments. As far as I can tell, Anthony is up to 4 posts in the series so far. Check them out here: part 1, part 2, part 3, and part 4. Enjoy!

Servers/Hardware

  • Good friend Simon Seagrave is back to the online world again with this heads-up on a potential NIC issue with an HP Proliant firmware update. The post also contains a link to a fix for the issue. Glad to see you back again, Simon!
  • Tom Howarth asks, “Is the x86 blade server dead?” (OK, so he didn’t use those words specifically. I’m paraphrasing for dramatic effect.) The basic premise of Tom’s position is that new technologies like server-side caching and VSAN/Ceph/Sanbolic (turning direct-attached storage into shared storage) will dramatically change the landscape of the data center. I would generally agree, although I’m not sure that I agree with Tom’s statement that “complexity is reduced” with these technologies. I think we’re just shifting the complexity to a different place, although it’s a place where I think we can better manage the complexity (and perhaps mask it). What do you think?

Security

Cloud Computing/Cloud Management

  • Juan Manuel Rey has launched a series of blog posts on deploying OpenStack with KVM and VMware NSX. He has three parts published so far; all good stuff. See part 1, part 2, and part 3.
  • Kyle Mestery brought to my attention (via Twitter) this list of the “best newly-available OpenStack guides and how-to’s”. It was good to see a couple of Cody Bunch’s articles on the list; Cody’s been producing some really useful OpenStack content recently.
  • I haven’t had the opportunity to use SaltStack yet, but I’m hearing good things about it. It’s always helpful (to me, at least) to be able to look at products in the context of solving a real-world problem, which is why seeing this post with details on using SaltStack to automate OpenStack deployment was helpful.
  • Here’s a heads-up on a potential issue with the vCAC 6.0.1.1 upgrade—the upgrade apparently changes some configuration files. The linked blog post provides more details on which files get changed. If you’re looking at doing this upgrade, read this to make sure you aren’t adversely affected.
  • Here’s a post with some additional information on OpenStack live migration that you might find useful.

Operating Systems/Applications

  • RHEL7, Docker, and Puppet together? Here’s a post on just such a use case (oh, I forgot to mention OpenStack’s involved, too).
  • Have you ever walked through a spider web because you didn’t see it ahead of time? (Not very fun.) Sometimes I feel that way with certain technologies or projects—like there are connections there with other technologies, projects, trends, etc., that aren’t quite “visible” just yet. That’s where I am right now with the recent hype around containers and how they are going to replace VMs. I’m not so sure I agree with that just yet…but I have more noodling to do on the topic.

Storage

  • “Server SAN” seems to be the name that is emerging to describe various technologies and architectures that create pools of storage from direct-attached storage (DAS). This would include products like VMware VSAN as well as projects like Ceph and others. Stu Miniman has a nice write-up on Server SAN over at Wikibon; if you’re not familiar with some of the architectures involved, that might be a good place to start. Also at Wikibon, David Floyer has a write-up on the rise of Server SAN that goes into a bit more detail on business and technology drivers, friction to adoption, and some recommendations.
  • Red Hat recently announced they were acquiring Inktank, the company behind the open source scale-out Ceph project. Jon Benedict, aka “Captain KVM,” weighs in with his thoughts on the matter. Of course, there’s no shortage of thoughts on the acquisition—a quick web search will prove that—but I find it interesting that none of the “big names” in storage social media had anything to say (not that I could find, anyway). Howard? Stephen? Chris? Martin? Bueller?

Virtualization

  • Doug Youd pulled together a nice summary of some of the issues and facts around routed vMotion (vMotion across layer 3 boundaries, such as across a Clos fabric/leaf-spine topology). It’s definitely worth a read (and not just because I get mentioned in the article, either—although that doesn’t hurt).
  • I’ve talked before—although it’s been a while—about Hyper-V’s choice to rely on host-level NIC teaming in order to provide network link redundancy to virtual machines. Ben Armstrong talks about another option, guest-level NIC teaming, in this post. I’m not so sure that using guest-level teaming is any better than relying on host-level NIC teaming; what’s really needed is a more full-featured virtual networking layer.
  • Want to run nested ESXi on vCHS? Well, it’s not supported…but William Lam shows you how anyway. Gotta love it!
  • Brian Graf shows you how to remove IP pools using PowerCLI.

Well, that’s it for this time around. As always, I welcome all courteous comments, so feel free to share your thoughts, ideas, rants, links, or feedback in the comments below.

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Reader Brian Markussen—with whom I had the pleasure to speak at the Danish VMUG in Copenhagen earlier this month—brought to my attention an issue between VMware vSphere’s health check feature and Cisco UCS when using Cisco’s VIC cards. His findings, confirmed by VMware support and documented in this KB article, show that the health check feature doesn’t work properly with Cisco UCS and the VIC cards.

Here’s a quote from the KB article:

The distributed switch network health check, including the VLAN, MTU, and teaming policy check can not function properly when there are hardware virtual NICs on the server platform. Examples of this include but are not limited to Broadcom Flex10 systems and Cisco UCS systems.

(Ignore the fact that “UCS systems” is redundant.)

According to Brian, a fix for this issue will be available in a future update to vSphere. In the meantime, there doesn’t appear to be any workaround, so plan accordingly.

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Welcome to part 13 of the Learning NSX blog series, in which I revisit the idea of logical networking with VMware NSX. This is a topic I first discussed in part 5 of this series, but I want to go back and look at it again, this time from a more practical perspective of what it looks like to use VMware NSX for logical networking in an OpenStack environment.

If you haven’t been keeping up with the Learning NVP/NSX series, you’ll probably want to go back and catch up. Links to all the articles are found on my Learning NVP/NSX page. You’ll particularly want to be sure that you’ve read part 11 and part 12, which cover the OpenStack integration I’ll be leveraging in this post.

To start things off, let’s first do a quick recap of what it looks like to manually create a logical network in VMware NSX (all of this is described in part 5 of the series):

  1. Create a logical switch.
  2. Add logical switch ports to the newly-created logical switch.
  3. Edit the attachment of the logical switch ports to connect a VM’s virtual network interface card (NIC).

These three steps will establish a simple logical network within VMware NSX. Of course, this logical network won’t have any Dynamic Host Configuration Protocol (DHCP) services, but it will still work (you could manually assign IP address to VMs attached to this logical network).

Now that we have VMware NSX integrated with OpenStack, let’s revisit this process to see what it looks like. (I’ll assume that you’re logged into the OpenStack dashboard and have the necessary permissions to create networks, launch instances, etc.)

First, you’d need to create a network in OpenStack. To do this, it’s as simple as selecting Networks > Create Network, then providing a name for the new network (you could also use the neutron net-create command as well):

Creating a logical network in OpenStack

To exactly mirror the process I showed you in part 5—which did not include DHCP services—you’d need to also go to the Subnet tab and uncheck “Create Subnet” as well as go to the Subnet Detail tab and uncheck “Enable DHCP.” Once you unselect those options and click Create, then OpenStack will (through the Neutron plugin for NSX) create a logical switch in NSX. You can pop into NSX Manager to see this:

New logical switch in NSX Manager

As I pointed out in part 12, the UUID and os_tid tag on this object in NSX will provide the necessary ties back to the corresponding object in OpenStack.

Now go spin up a new instance and attach that instance to the logical network you just created. What you’ll find is that OpenStack will automatically handle the creation of the logical switch ports as well as the attachment of the VM’s virtual NIC to the logical switch. This helps underscore how VMware NSX was designed to be used in conjunction with a cloud management/orchestration system like OpenStack. (You can verify that the logical switch port is automatically created using NSX Manager and comparing the number of logical switch ports both before and after launching the new instance.)

Now that we have OpenStack up and running, though, we can create a logical network that does have DHCP services:

  1. Use the neutron net-create command to create a new logical network:
  2. neutron net-create logical-net-02
  3. Use neutron subnet-create to create a subnet for the new network:
  4. neutron subnet-create --name logical-subnet-02 logical-net-02 10.1.1.0/24

If you log into NSX Manager, you’ll see that a new logical switch (whose name matches the name you gave the logical network above) has been created, and you’ll also note that 1 logical switch port is already in use—even though you haven’t launched any instances yet! The easiest way to find out what is attached to that port is via the OpenStack dashboard. Once logged into the dashboard, select Networks, then click on the network you just created, and scroll down to the list of Ports. You’ll see there that OpenStack has automatically created a logical switch port for the DHCP services associated with the subnet you created above:

Ports on a logical network

If you’re a command-line freak, you could also get this information from the CLI:

  1. Find the subnet associated with the logical network you just created:
  2. SUBNET_ID=$(neutron subnet-list | awk '/\ logical-net-02\ / {print $2}')
  3. List all the ports on that subnet:
  4. neutron port-list | grep $SUBNET_ID
  5. In this case, there is only one port on that subnet, so you can capture the ID of that port in order to get more information about the port:
  6. PORT_ID=$(neutron port-list | grep $SUBNET_ID | awk '{print $2}')
  7. List the information associated with that specific port, paying particular attention to the device_owner attribute (which should show “network:dhcp”):
  8. neutron port-show $PORT_ID

If you have been reading along diligently, you’ll probably be able to put 2 and 2 together here to realize that the “network:dhcp” port is actually a port on OVS on the network node (which, if you’ll recall, is registered as a hypervisor in VMware NSX). If you’ve really been following my stuff closely, you’ll probably also know that the OVS port is connected to a veth pair, which in turn connects to a network namespace where an instance of dnsmasq is running. (Want to learn more about network namespaces? See here.)

At this point, you should have a fairly clear understanding of how logical networking functions within an OpenStack environment with VMware NSX. I wanted to take the time to revisit this topic because future posts are going to assume that you understand these basic concepts and interactions as we explore more advanced functionality and more complex networking topologies.

Thanks for reading, and feel free to post any corrections, clarifications, or questions in the comments below.

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Welcome to part 12 of the Learning NSX blog series, in which I continue the discussion around integration between OpenStack and VMware NSX, and in which I’ll provide more details about how exactly to integrate them.

If you are just now joining the series, I encourage you to visit the Learning NVP/NSX page, where you can find links to all the posts in the series. While you’ll want to be caught up on all the posts (they do build on one another in various ways), in particular you’ll want to make sure you’ve read part 11. Part 11 covers the basics of VMware NSX-OpenStack integration, and explains how the various components of OpenStack Neutron and VMware NSX will interact.

Once you understand how the different components of Neutron and NSX will interact, getting NSX integrated into OpenStack Neutron isn’t too terribly difficult. The basic steps look like this:

  1. Install the VMware NSX plugin for Neutron.
  2. Configure VMware NSX for Neutron.
  3. Configure Neutron for VMware NSX.

Let’s take a more in-depth look at each of these steps.

Installing the VMware NSX plugin for Neutron

VMware distributes a set of compiled binary packages for OpenStack Neutron plus the VMware NSX plugin from the VMware NSX support portal (available to VMware NSX customers). Source code is also available, if you’d prefer that. These builds provided by VMware represent the latest fixes to both Neutron and NSX based off the “official” OpenStack Neutron releases. A single download contains all the different components of Neutron that you need (it’s a tarred and gzipped file that you just unpack).

Once you have the packages (I’ll assume you’re using Ubuntu and therefore have downloaded and will use the Debian packages), then you can just use dpkg -i to install the appropriate package(s) on the appropriate node(s). Recall from part 11 that when implementing Neutron with VMware NSX, you’ll need both a Neutron server as well as a network node running the DHCP and metadata agents. Here’s a breakdown of which packages need to be installed on which nodes:

  • On the Neutron server, you’d install neutron-common, neutron-server, python-neutron, and neutron-plugin-nicira.
  • On the Neutron network node, you’d install (at a minimum) neutron-common, neutron-dhcp-agent, and neutron-metadata-agent. If you wanted LBaaS support, you’d also install neutron-lbaas-agent. You could optionally install the Python client with python-neutron as well.

From here, you would proceed with setting up OpenStack Neutron as outlined in a variety of places, including the official OpenStack docs. If you do choose to use the official docs to get Neutron configured, here’s how the breakdown of the instructions map to the setup you’d need to build for use with VMware NSX:

  • The “Installing networking support on a dedicated controller node” section contains information for setting up Neutron on an OpenStack controller that does not run any of the underlying agents. Typically, this system would also run the API servers for some of the other OpenStack services as well (like Nova, Cinder, or Glance).
  • The “Installing networking support on a dedicated network node” section contains the information for setting up a network node that would run the DHCP and metadata agents. Recall that you don’t need the L3 agent, since that is handled by NSX. It might include the LBaaS agent, if you need that functionality.
  • The “Installing networking support on a dedicated compute node” section has the information for setting up your OpenStack compute nodes to interact with Neutron appropriately. Note that you don’t need to install an agent on the compute nodes; adding the compute nodes to NSX (as described in part 4) establishes the necessary communication between the NSX controllers and the compute nodes.

This helps you get Neutron up and running; in the “Configuring Neutron for VMware NSX” section below, I’ll provide additional specifics around how to configure Neutron to communicate with VMware NSX. For now, let’s make sure that VMware NSX is ready for Neutron.

Configuring VMware NSX for Neutron

VMware NSX was designed to be cloud platform-agnostic, so there isn’t a whole lot that needs to be done here. There are, however, a few tasks you’ll want to make sure you’ve done inside VMware NSX:

  1. You’ll want to ensure that you’ve added at least one NSX gateway appliance to your installation. (Part 6 describes how to add an NVP/NSX gateway appliance.)
  2. You’ll want to ensure that you’ve added an L3 gateway service, as described in part 9 of the series. The L3 gateway service replaces the L3 agent in OpenStack Neutron and is therefore necessary to provide routed/NAT’d connectivity into or out of logical (tenant) networks. Use NSX Manager to get the UUID of the L3 gateway service you’ve added; we’ll need that when we configure Neutron.
  3. You’ll need to make sure you’ve already created a transport zone, as described in part 4 and explained in greater detail in part 5. Use NSX Manager to get the UUID of the transport zone that you want Neutron to use when creating overlay networks; you’ll need that when configuring the NSX plugin for Neutron.

Configuring Neutron for VMware NSX

Now, let’s get into some nitty gritty specifics on how we configure OpenStack Neutron to interact with VMware NSX.

Most of the configuration is done within the NSX-specific configuration files, but there are two settings in neutron.conf on the controller node (where the Neutron API server is running) that you’ll want to set:

  • You’ll absolutely want to set the core_plugin value to neutron.plugins.nicira.NeutronPlugin.NvpPluginV2. (Note that in future releases of the NSX plugin, the name may change from “nicira” and “Nvp” to “vmware” and “Nsx”.)
  • You’ll probably also want to set allow_overlapping_ips to True so that Nova metadata works as you would expect. (I’ll have more on that in a moment.)

The bulk of the rest of the configuration is found in nvp.ini, which is typically found in the /etc/neutron/plugins/nicira directory. Here are the relevant settings that you’ll want to configure:

  • You’ll want to set nvp_user and nvp_password appropriately for your VMware NSX installation.
  • Populate the nvp_controllers line with the addresses of the NSX controllers in your environment, in the form “W.X.Y.Z:443″. Separate the controllers’ IP addresses with commas.
  • Place the UUID of the transport zone that you want Neutron to use when creating overlay networks as the value for default_tz_uuid.
  • Place the UUID of the L3 gateway service that you want Neutron to use when creating logical routers with external gateways as the value for the default_l3_gw_service_uuid entry.
  • In the [database] section, make sure there is an appropriate MySQL connection entry for the Neutron database (assuming you are using MySQL). An example connection entry might look like “mysql://neutron:[email protected]/neutron” (or similar).
  • There are a couple different ways to provide Nova metadata to the instances; I prefer using a special metadata access network (I’ll likely talk more about that in a future post). To use this configuration, set metadata_mode to “access_network” and set enable_metadata_access_network to True. (You may also need to set metadata_dhcp_host_route to False.)

That should be all the settings you need on the controller node. However, you’ll also need to slightly configure the DHCP and metadata agents on the network node:

  • In the dhcp_agent.ini file, set enable_isolated_metadata and enable_metadata_network to True. If your Linux distribution supports network namespaces (Ubuntu does), then also set use_namespaces to True.
  • The metadata agent does not require any special configuration above and beyond what is needed to get Neutron running.

Once you restart all relevant services so that they pick up the new settings, you should have Neutron talking to VMware NSX correctly. To test if everything is working correctly, use the Neutron CLI to create a logical network:

neutron net-create test-network

In my environment (running OpenStack Havana and NSX 4.0.0), that produced output that looked like this:

Neutron CLI output

If all is working as expected, then you should see a matching logical switch listed in NSX Manager:

Logical switches in NSX Manager

(Click the image above for a larger version.)

It may be obvious, but you’ll note that the ID returned by the neutron net-create command matches the UUID listed in NSX Manager. You’ll also note that the os_tid tag assigned to the logical switch in NSX Manager matches the tenant ID of the tenant who owns the logical switch in OpenStack. Finally, you’ll note that the bound transport zone’s UUID will match the UUID you specified in nvp.ini as I outlined earlier.

That’s it—you now have VMware NSX integrated with OpenStack Neutron!

In the next post, I’ll revisit the topic of logical networking and logical switches within VMware NSX, something I first discussed fairly early in the series. Once I’ve reviewed some concepts and established a firm foundation, future posts will take a look at how to take advantage of a very cool feature within VMware NSX: the distributed logical router.

In the meantime, feel free to post any questions, clarifications, or thoughts in the comments below. Please include any vendor affiliations, where applicable; otherwise, all courteous comments are welcome!

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Welcome to Technology Short Take #40. The content is a bit light this time around; I thought I’d give you, my readers, a little break. Hopefully there’s still some useful and interesting stuff here. Enjoy!

Networking

  • Bob McCouch has a nice write-up on options for VPNs to AWS. If you’re needing to build out such a solution, you might want to read his post for some additional perspectives.
  • Matthew Brender touches on a networking issue present in VMware ESXi with regard to VMkernel multi-homing. This is something others have touched on before (including myself, back in 2008—not 2006 as I tweeted one day), but Matt’s write-up is concise and to the point. You’ll definitely want to keep this consideration in mind for your designs. Another thing to consider: vSphere 5.5 introduces the idea of multiple TCP/IP stacks, each with its own routing table. As the ability to use multiple TCP/IP stacks extends throughout vSphere, it’s entirely possible this limitation will go away entirely.
  • YAOFC (Yet Another OpenFlow Controller), interesting only because it focuses on issues of scale (tens of thousands of switches with hundreds of thousands of endpoints). See here for details.

Servers/Hardware

  • Intel recently announced a refresh of the E5 CPU line; Kevin Houston has more details here.

Security

  • This one slipped past me in the last Technology Short Take, so I wanted to be sure to include it here. Mike Foley—whom I’m sure many of you know—recently published an ESXi security whitepaper. His blog post provides more details, as well as a link to download the whitepaper.
  • The OpenSSL “Heartbleed” vulnerability has captured a great deal of attention (justifiably so). Here’s a quick article on how to assess if your Linux-based server is affected.

Cloud Computing/Cloud Management

  • I recently built a Windows Server 2008 R2 image for use in my OpenStack home lab. This isn’t as straightforward as building a Linux image (no surprises there), but I did find a few good articles that helped along the way. If you find yourself needing to build a Windows image for OpenStack, check out creating a Windows image on OpenStack (via Gridcentric) and building a Windows image for OpenStack (via Brent Salisbury). You might also check out Cloudbase.it, which offers a version of cloud-init for Windows as well as some prebuilt evaluation images. (Note: I was unable to get the prebuilt images to download, but YMMV.)
  • Speaking of building OpenStack images, here’s a “how to” guide on building a Debian 7 cloud image for OpenStack.
  • Sean Roberts recently launched a series of blog posts about various OpenStack projects that he feels are important. The first project he highlights is Congress, a policy management project that has recently gotten a fair bit of attention (see a reference to Congress at the end of this recent article on the mixed messages from Cisco on OpFlex). In my opinion, Congress is a big deal, and I’m really looking forward to seeing how it evolves.
  • I have a related item below under Virtualization, but I wanted to point this out here: work is being done on a VIF driver to connect Docker containers to Open vSwitch (and thus to OpenStack Neutron). Very cool. See here for details.
  • I love that Cody Bunch thinks a lot like I do, like this quote from a recent post sharing some links on OpenStack Heat: “That generally means I’ve got way too many browser tabs open at the moment and need to shut some down. Thus, here comes a huge list of OpenStack links and resources.” Classic! Anyway, check out the list of Heat resources, you’re bound to find something useful there.

Operating Systems/Applications

  • A short while back I had a Twitter conversation about spinning up a Minecraft server for my kids in my OpenStack home lab. That led to a few other discussions, one of which was how cool it would be if you could use Heat autoscaling to scale Minecraft. Then someone sends me this.
  • Per the Microsoft Windows Server Team’s blog post, the Windows Server 2012 R2 Udpate is now generally available (there’s also a corresponding update for Windows 8.1).

Storage

  • Did you see that EMC released a virtual edition of VPLEX? It’s being called the “data plane” for software-defined storage. VPLEX is an interesting product, no doubt, and the introduction of a virtual edition is intriguing (but not entirely unexpected). I did find it unusual that the release of the virtual edition signalled the addition of a new feature called “MetroPoint”, which allows two sites to replicate back to a single site. See Chad Sakac’s blog post for more details.
  • This discussion on MPIO and in-guest iSCSI is a great reminder that designing solutions in a virtualized data center (or, dare I say it—a software-defined data center?) isn’t the same as designing solutions in a non-virtualized environment.

Virtualization

  • Ben Armstrong talks briefly about Hyper-V protected networks, which is a way to protect a VM against network outage by migrating the VM to a different host if a link failure occurs. This is kind of handy, but requires Windows Server clustering in order to function (since live migration in Hyper-V requires Windows Server clustering). A question for readers: is Windows Server clustering still much the same as it was in years past? It was a great solution in years past, but now it seems outdated.
  • At the same time, though, Microsoft is making some useful networking features easily accessible in Hyper-V. Two more of Ben’s articles show off the DHCP Guard and Router Guard features available in Hyper-V on Windows Server 2012.
  • There have been a pretty fair number of posts talking about nested ESXi (ESXi running as a VM on another hypervisor), either on top of ESXi or on top of VMware Fusion/VMware Workstation. What I hadn’t seen—until now—was how to get that working with OpenStack. Here’s how Mathias Ewald made it work.
  • And while we’re talking nested hypervisors, be sure to check out William Lam’s post on running a nested Xen hypervisor with VMware Tools on ESXi.
  • Check out this potential way to connect Docker containers with Open vSwitch (which then in turn opens up all kinds of other possibilities).
  • Jason Boche regales us with a tale of a vCenter 5.5 Update 1 upgrade that results in missing storage providers. Along the way, he also shares some useful information about Profile-Driven Storage in general.
  • Eric Gray shares information on how to prepare an ESXi ISO for PXE booting.
  • PowerCLI 5.5 R2 has some nice new features. Skip over to Alan Renouf’s blog to read up on what is included in this latest release.

I should close things out now, but I do have one final link to share. I really enjoyed Nick Marshall’s recent post about the power of a tweet. In the post, Nick shares how three tweets—one with Duncan Epping, one with Cody Bunch, and one with me—have dramatically altered his life and his career. It’s pretty cool, if you think about it.

Anyway, enough is enough. I hope that you found something useful here. I encourage readers to contribute to the discussion in the comments below. All courteous comments are welcome.

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Some time ago, I introduced you to the idea of Linux network namespaces, and provided an overview of some of the commands needed to interact with network namespaces. In this post, I’ll follow up on that post with some additional information on using network namespaces with other types of network interfaces.

In the previous network namespaces article, I mentioned (incorrectly, it turns out) that you had to use virtual Ethernet (veth) interfaces in order to connect a namespace to the physical network:

It turns out you can only assign virtual Ethernet (veth) interfaces to a network namespace.

I say “incorrectly” because you are able to assign more than just virtual Ethernet interfaces to a Linux network namespace. I’m not sure why I arrived at that conclusion, because subsequent testing—using Ubuntu 12.04 LTS as with the original testing—showed no problem assigning physical interfaces to a particular network namespace. The VMs I used for the subsequent testing are using a different kernel (the 3.11 kernel instead of whatever I used in the previous testing), so it’s entirely possible that’s the difference. If I get the opportunity, I’ll try with earlier kernel builds to see if that makes any difference.

In any case, assigning other types of network interfaces to a network namespace is just like assigning veth interfaces. First, you create the network namespace:

ip netns add <new namespace name>

Then, you’d assign the interface to the namespace:

ip link set <device name> netns <namespace name>

For example, if you wanted to assign eth1 to the “blue” namespace, you’d run this:

ip link set eth1 netns blue

Please note that I haven’t found a way to unassign an interface from a network namespace other than deleting the namespace entirely.

If you want to assign a VLAN interface to a namespace, the process is slightly different. You’ll have to create the namespace first, as with physical and veth interfaces, but you’ll also have to create the VLAN interface in the “default” namespace first, then move it over to the desired namespace.

For example, first you’d create the namespace “red”:

ip netns add red

Then you’d create the VLAN interface for VLAN 100 on physical interface eth1:

ip link add link eth1 name eth1.100 type vlan id 100

The generic form of this command is this:

ip link add link <physical device> name <VLAN device name> type vlan id <VLAN ID>

Note that you can’t use ip netns exec to run the command to create the VLAN interface in the network namespace directly; it won’t work because the parent interface upon which the VLAN interface is based doesn’t exist in the namespace. So you’ll create the VLAN interface in the default namespace first, then move it over.

Once the VLAN interface is created, then move it to the target namespace:

ip link set eth1.100 netns red

One (sort of) interesting thing I noted in my testing was that link status and IP addresses don’t move between namespaces. Therefore, don’t bother assigning an IP address or setting the link state of an interface before you move it to the final namespace, because you’ll just have to do it again.

To make the interface functional inside the target namespace, you’ll use ip netns exec to target the specific configuration commands against the desired namespace. For example, if the VLAN interface eth1.100 exists in the namespace “blue”, you’d run these commands:

ip netns exec blue ip addr add 10.1.1.1/24 dev eth1.100

That adds the IP address to the interface in the namespace; then you’d use this command to set the link status to up:

ip netns exec blue ip link set eth1.100 up

Then you can test network connectivity with our good friend ping like this:

ip netns exec blue ping -c 4 10.1.1.2

(Obviously, you’d want to substitute an appropriate IP address there for your specific configuration and environment.)

I hope this additional information on working with Linux network namespaces is useful. As always, I invite and encourage any questions, thoughts, or corrections in the comments below. All courteous comments are welcome!

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Welcome to part 11 of the Learning NSX blog series, in which I provide a high-level overview of the basics on integrating VMware NSX into an OpenStack deployment using OpenStack Neutron. In case you’re just now catching up on this blog series, I encourage you to visit my Learning NVP/NSX page, which has a brief summary of all the posts in the series.

Now that I shown you how to build all the different components of NSX (NSX controllers, NSX Manager, gateway appliances, and service nodes), it’s time to add integration into a cloud management platform. VMware NSX was designed to be integrated into a cloud management platform. Because VMware NSX offers a full-featured RESTful API, you could—in theory—integrate NSX into just about any cloud management platform. However, for the purposes of this series, I’ll limit the discussion to focus on how one would integrate VMware NSX with OpenStack via the OpenStack Neutron (formerly “Quantum”) project, which provides virtual networking functionality for OpenStack-based clouds.

The challenge in discussing OpenStack-NSX integration is that one must first understand the basics of OpenStack Neutron before looking at how to integrate VMware NSX into Neutron. Therefore, the primary goal of this post in the series is to provide an overview of Neutron, and then discuss how NSX integrates into Neutron. The next post in the series will provide more in-depth technical details on exactly how the integration is configured.

Let’s start with a generic overview of OpenStack Neutron and its components.

Examining OpenStack Neutron Components

OpenStack Neutron itself has a number of different components:

  • The Neutron server, which supplies the Neutron API and is typically—but not required to be—deployed co-resident on an OpenStack “controller” node (not to be confused with an NSX controller).
  • The Neutron DHCP agent, which provides DHCP services for the various logical networks created in Neutron (at least, whenever DHCP is enabled for a logical network).
  • The Neutron L3 agent, which provides L3 (routed) connectivity for Neutron logical networks. This includes both L3 between logical networks as well as L3 in and out of logical networks.
  • The Neutron metadata agent, which is responsible for providing connectivity between instances and the Nova metadata service (for customizing instances appropriately).
  • Finally, for many Open vSwitch (OVS)-based installations, there is the Neutron OVS agent, which provides a way to program OVS to do what Neutron needs it to do.

The Neutron DHCP, L3, and metadata agents are typically—but not required to be—installed on a so-called “network” node. This network node thus provides DHCP services to the various logical networks (often using Linux network namespaces, if the Linux distribution supports them), routed connectivity in and out of logical networks (once again with network namespaces, Linux bridges, and iptables rules), and metadata service connectivity.

From a traffic flow perspective, traffic from one subnet in a logical network to another subnet in a logical network must hairpin through the network node (where the L3 agent resides). Traffic headed out of a logical network must flow through the network node, where iptables rules will perform the necessary network address translation (NAT) functions associated with the use of floating IPs in an OpenStack environment. And, as I’ve already mentioned, the network node provides DHCP services to all the logical networks as well.

This is, by necessity, a very high-level overview of OpenStack Neutron and the core components. Let’s now take a look at how these components are affected when you choose to use VMware NSX with OpenStack Neutron.

Reviewing OpenStack Neutron With NSX

When you’re using VMware NSX as the mechanism behind OpenStack Neutron, some of Neutron’s functionality is provided by NSX itself:

  • You no longer need the L3 agent. L3 connectivity is provided by the NSX gateway appliances and logical gateway services (refer to part 6 and part 9 of the series, respectively).
  • You won’t need the OVS agent on the hypervisors, because the NSX controllers are responsible for configuring/programming OVS on transport nodes. More details on this interaction is provided in part 4 of the series. (Transport nodes is a generic term referring to nodes that participate in the data plane, such as hypervisors, gateways, and service nodes.)
  • You will still need the Neutron server, the DHCP agent, and the metadata agent.

Therefore, if you choose to deploy the OpenStack Neutron components in a “typical” fashion, you’d have a setup something like this:

  • An OpenStack “controller” node would host the Neutron server, which provides the API with which other parts of OpenStack will interact. This node generally does not have OVS installed, but would have the NSX plugin for Neutron installed. This plugin implements the integration between OpenStack and NSX, and will communicate with NSX via the NSX northbound RESTful API.
  • An OpenStack “network” node would host the Neutron DHCP agent and the Neutron metadata agent. This node would have OVS installed, and would be registered into NSX as a hypervisor (even though it is not a hypervisor and will not host any VMs).

At this point, you should have a pretty good understanding of how, at a high level, NSX integrates with and affects OpenStack Neutron. In the next post in the series, I’ll provide more details on exactly how to configure the integration between VMware NSX and OpenStack Neutron.

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