Thanks to everyone who took the time to comment on the first half of scenario 3, both here and on twitter. There were many great suggestions, and some were spot-on!
For more detail on the problem, some diagrams and other scoping information, be sure to check out the first half of scenario 3.
During the initial scoping in the first half, we didn’t really see too much out of the ordinary in the UI aside from some odd ‘red alarm’ exclamation marks on the compute-r hosts in the Host Preparation section.
More than one commenter pointed out that this needs to be investigated. I wholeheartedly agree. Despite seeing a green status for host VIB installation, firewall status and VXLAN, there is clearly still a problem. That problem is related to ‘Communication Channel Health’.
The communication channel health check was a new feature added in NSX 6.2 and makes it easy to see which hosts are having problems communicating with both NSX Manager and the Control Cluster. In our case, both esx-r1 and esx-r2 are reporting problems with their control plane agent (netcpa) to all three controllers.
Welcome to the third installment of my new NSX troubleshooting series. What I hope to do in these posts is share some of the common issues I run across from day to day. Each scenario will be a two-part post. The first will be an outline of the symptoms and problem statement along with bits of information from the environment. The second will be the solution, including the troubleshooting and investigation I did to get there.
NSX Troubleshooting Scenario 3
I’ll start off again with a brief customer problem description:
“We’ve recently deployed Cross-vCenter NSX for a remote datacenter location. All of the VMs at that location don’t have connectivity. They can’t ping their gateway, nor can they ping VMs on other hosts. Only VMs on the same host can ping each other.”
This is a pretty vague description of the problem, so let’s have a closer look at this environment. To begin, let’s look at the high-level physical interconnection between datacenters in the following diagram:
There isn’t a lot of detail above, but it helps to give us some talking points. The main location is depicted on the left. A three host cluster called compute-a exists there. All of the VLAN backed networks route through a router called vyos. The Universal Control Cluster exists at this location, as does the primary NSX manager.
If you are new to NSX or looking to evaluate it in the lab, there is one very common issue that you may run into. After going through the initial steps of deploying and registering NSX Manager with vCenter, you may be surprised to find that there are no manageable NSX managers listed under ‘Networking and Security’ in the Web Client. Although the registration and Web Client plugin installation appears successful, there is often an extra step needed before you can manage things.
One of the first tasks involved in deploying NSX is to register NSX Manager with a vCenter Server. This is done for inventory management and synchronization purposes. The NSX Manager can be optionally registered with SSO as well.
The vCenter user that is used for registration needs to have the highest level of privileges for NSX to work correctly. The NSX install guide clearly states that this must be the vCenter ‘Administrator’ role.
From the NSX Install Guide:
“You must have a vCenter Server user account with the Administrator role to synchronize NSX Manager with the vCenter Server. If your vCenter password has non-ASCII characters, you must change it before synchronizing the NSX Manager with the vCenter Server.”
Because of these requirements, it’s quite common to use the SSO administrator account – usually email@example.com. A service account is also often created for this purpose to more easily identify and distinguish NSX tasks. Either way, these are not normally accounts that you’d use for day-to-day administration in vSphere.
By default, NSX will only assign its ‘Enterprise Administrator’ role to the user account that was used to register it with vCenter Server. This means that by default, only that specific vCenter user will have access to the NSX manager from within the Web Client.
That said, if you are experiencing this problem, you are probably not logged in with the vCenter user that was used for registration purposes. To grant access to other users, you’ll need to log into the vSphere Web Client using the registration user account, and then add additional users and groups.
In my lab, I’ve just logged in with an active directory user called ‘firstname.lastname@example.org’. This user has full administrator privileges in vCenter, but has no access to any NSX Managers:
If I log out, and log back in with the email@example.com account that was used for vCenter registration, I can see the NSX managers that were registered.
In my lab, I’ve got a secondary deployed as well, but we’ll focus only on 172.16.10.40. If I click on that manager in the list, I’m able to go to the ‘Users’ tab to see what the default permissions look like:
As you can see, only one user – the SSO administrator account used for registration – has the requisite role for administrator via the Web Client. In my lab, I want to provide full access to an AD group called ‘VMware Admins’ and an individual user called ‘Test’.
Both vCenter users and groups can be specified here. As long as vCenter can authenticate them – either via SSO, local authentication or even AD – they are fair game.
Another common mistake made is selecting the NSX Administrator role rather than Enterprise Administrator. NSX Administrator sounds like the highest privilege level, but it’s actually Enterprise Administrator that gives you all the keys to the kingdom. You won’t be able to administer certain things – including user permissions – unless Enterprise Administrator is chosen.
Once this is done, you’ll see the users and groups listed and should now have the correct permissions to administer the NSX deployment!
Keep in mind that if you’ve got more than one NSX manager deployed, you’ll need to set this on each independently.
Have any questions or want more information? Please feel free to leave a comment below or reach out to me on Twitter (@vswitchzero)
Welcome to the second installment of a new series of NSX troubleshooting scenarios. This is the second half of scenario two, where I’ll perform some troubleshooting and resolve the problem.
Please see the first half for more detail on the problem symptoms and some scoping.
As mentioned in the first half, the problem is limited to a host called esx-a1. As soon as a guest moves to that host, it has no network connectivity. If we move a guest off of the host, its connectivity is restored.
We have one VM called win-a1 on host esx-a1 for testing purposes at the moment. As expected, the VM can’t be reached.
To begin, let’s have a look at the host from the CLI to figure out what’s going on. We know that the UI is reporting that it’s not prepared and that it doesn’t have any VTEPs created. In reality, we know a VTEP exists but let’s confirm.
To begin, we’ll check to see if any of the VIBs are installed on this host. With NSX 6.3.x, we expect to see two VIBs listed – esx-vsip and esx-vxlan.
I got some overwhelmingly positive feedback after posting the first troubleshooting scenario and solution recently. Thanks to everyone who reached out to me via Twitter with feedback and suggestions! Please keep those suggestions and comments coming.
Today, I’m going to post a similar but more brief scenario. This is something that we see regularly in GSS – issues surrounding host preparation!
NSX Troubleshooting Scenario 2
Let’s begin with the usual vague customer problem description:
“We took a host out of the compute-a cluster to do some hardware maintenance. Now it’s been added back and when VMs move to this host, they have no connectivity! We’re using NSX 6.3.2”
This is a fictional scenario of course, but let’s assume that we’ve started taking a look at the environment and collecting some additional data.
As the customer mentioned, they are running NSX 6.3.2 and have a cluster called compute-a:
The host that was taken out of the cluster for maintenance was esx-a1.lab.local. Similar to the previous scenario, the L3 design is pretty much the same:
Welcome to the second half of ‘NSX Troubleshooting Scenario 1’ . For detail on the problem and some initial scoping, please see the first part of the scenario that I posted a few days ago. In this half, I’ll walk through some of the troubleshooting I did to find the underlying cause of this problem as well as the solution.
Where to Start?
The scoping done in the previous post gives us a lot of useful information, but it’s not always clear where to start. In my experience, it’s helpful to make educated ‘assertions’ based on what I think the issue is – or more often what I think the issue is not.
I’ll begin by translating the scoping observations into statements:
It’s clear that basic L2/L3 connectivity is working to some degree. This isn’t a guarantee that there aren’t other problems, but it looks okay at a glance.
We know that win-b1 and web-a1 are both on the same VXLAN logical switch. We also know they are in the same subnet, so that eliminates a lot of the routing as a potential problem. The DLR and ESGs should not really be in the picture here at all.
The DFW is enabled, but looks to be configured with the default ‘allow’ rules only. It’s unlikely that this is a DFW problem, but we may need to prove this because the symptoms seem to be specific to HTTP.
We also know that VMs in the compute-b cluster are having the same types of symptoms accessing internet based web sites. We know that the infrastructure needed to get to the internet – ESGs, physical routers etc– are all accessed via the compute-a cluster.
It was also mentioned by the customer that the compute-b cluster was newly added. This may seem like an insignificant detail, but really increases the likelihood of a configuration or preparation problem.
Based on the testing done so far, the issue appears to be impacting a TCP service – port 80 HTTP. ICMP doesn’t seem impacted. We don’t know if other protocols are seeing similar issues.
Before we start health checking various NSX components, let’s do a bit more scoping to see if we can’t narrow this problem down even further. Right off the bat, the two questions I want answered are:
Are we really talking to the device we expect from a L2 perspective?
Is the problem really limited to the HTTP protocol?
Welcome to the first of what I hope to be many NSX troubleshooting posts. As someone who has been working in back-line support for many years, troubleshooting is really the bread and butter of what I do every day. Solving problems in vSphere can be challenging enough, but NSX adds another thick layer of complexity to wrap your head around.
I find that there is a lot of NSX documentation out there but most of it is on to how to configure NSX and how it works – not a whole lot on troubleshooting. What I hope to do in these posts is spark some conversation and share some of the common issues I run across from day to day. Each scenario will hopefully be a two-part post. The first will be an outline of the symptoms and problem statement along with bits of information from the environment. The second will be the solution, including the troubleshooting and investigation I did to get there. I hope to leave a gap of a few days between the problem and solution posts to give people some time to comment, ask questions and provide their thoughts on what the problem could be!
NSX Troubleshooting Scenario 1
As always, let’s start with a somewhat vague customer problem description:
“Help! I’ve deployed a new cluster (compute-b) and for some reason I can’t access internal web sites on the compute-a cluster or at any other internet site.”
Of course, this is really only a small description of what the customer believes the problem to be. One of the key tasks for anyone working in support is to scope the problem and put together an accurate problem statement. But before we begin, let’s have a look at the customer’s environment to better understand how the new compute-b cluster fits into the grand scheme of things.