Loading

×Sorry to interrupt
This page has an error. You might just need to refresh it.
[NoErrorObjectAvailable] Uncaught ReferenceError: addCTracking is not defined
Failing descriptor: {markup://c:KM_ArticleThemeLayout}

Refresh

Cookie Preference Center

General Information on cookies

When you visit our website, we use cookies to ensure that we give you the best experience. This information does not usually directly identify you, but it can give you a more personalized web experience. Because we respect your right to privacy, you can choose not to allow some types of cookies by clicking on the different category headings to find out more and change your settings. However, blocking some types of cookies may impact your experience on the site and the services we are able to offer. Further information can be found in our

Cookie Policy.

Strictly Necessary

Strictly Necessary

Always Active

Strictly Necessary

Strictly necessary cookies are always enabled since they are essential for our website to function. They enable core functionality such as security, network management, and website accessibility. You can set your browser to block or alert you about these cookies, but this may affect how the website functions. For more information please visit www.aboutcookies.org or www.allaboutcookies.org.

Cookie Details‎

Performance

Performance

Performance

Performance cookies are used to analyze the user experience to improve our website by collecting and reporting information on how you use it. They allow us to know which pages are the most and least popular, see how visitors move around the site, optimize our website and make it easier to navigate.

Cookie Details‎

Please confirm your settings by refreshing the page.

Functional

Functional

Functional

Functional cookies help us keep track of your past browsing choices so we can improve usability and customize your experience. These cookies enable the website to remember your preferred settings, language preferences, location and other customizable elements such as font or text size. If you do not allow these cookies, then some or all of these services may not function properly.

Cookie Details‎

Advertising

Advertising

Advertising

Advertising cookies are used to send you relevant advertising and promotional information. They may be set through our site by third parties to build a profile of your interests and show you relevant advertisements on other sites. These cookies do not directly store personal information, but their function is based on uniquely identifying your browser and internet device.

Cookie Details‎

Advertising Cookies

Consent Leg.Interest

Select All Vendors

Select All Vendors

Select All Hosts

Select All

Clear Filters

Information storage and access

Apply

Confirm My Choices Reject All Allow All

My Subscriptions

Loading

Knowledge Base

Intermittent Packet loss on VXLAN network in NSX (52530)

Last Updated: 5/31/2018Categories: TroubleshootingTotal Views: 7748Language:
English

Subscribe to get an email
newsletter with new updates

Please provide article feedback:

Symptoms

Unknown unicast flooding in one or more VXLANs leading to poor performance.

Intermittent packet loss on VXLAN networks.

Running the net-vdl2 -l command displays 1024 MAC Addresses learned on a problematic VNI.

VXLAN network: 5000

Multicast IP: N/A (headend replication)
Control plane: Enabled (multicast proxy,ARP proxy)
Controller: 10.0.0.1 (up)
MAC entry count: 1024 -- MAX Mac limit of 1024 Reached.
ARP entry count: 0
Port count: 2

The VDL2 counters for the VNI displays the "mac.update.full" counter incrementing in value.

net-vdl2 -S -s TENANT_VTEP -n 8007

mac.lookup.flood: 58193648
mac.lookup.full: 3356910
mac.update.learn: 0
mac.update.extend: 0

mac.update.full: 439420396  <---------This counter will continue to Increase.

Cause

This issue occurred because earlier versions of NSX for vSphere had a maximum MAC address limit of 1024 per VNI/Host. Once this limit was exceeded, the traffic for the Destination MAC Addresses was flooded across the VNI leading to poor performance.

Note: Mac address learning occurs when there is any broadcast/unknown unicast or Multicast traffic received on a given VNI on an ESXi host, even though the virtual machines on the ESXi host are not communicating. The maximum limit of 1024 MAC Addresses is per VNI/Host.

As part of the DLR ARP resolution process, the DLR uses an ARP proxy mechanism that may result in ESXi hosts learning the DLR pMAC addresses of other prepared ESXi hosts in the Transport Zone.
These MAC addresses are stored in the same MAC table that is used for VMs and therefore the maximum number of VM MAC addresses per host per VNI will actually be less than 1024.
This can explain why the MAC entry count may be at 1024 but the number of VM MAC addresses is lower.
The DLR ARP Suppression feature can reduce DLR ARP traffic. By reducing the number of DLR pMAC addresses learnt by a host, it can allow more VM MAC addresses to be learnt.
DLR ARP Suppression is fully functional on NSX 6.4.0. For earlier releases of NSX see Workaround section.

Resolution

NSX for vSphere versions 6.4.0/6.3.6 and above versions increased the maximum MAC count per VNI per host from 1024 to 2048.

Workaround

To work around this issue, segment VXLAN networks with limit of 1024 MAC entries per VXLAN segment.
The DLR ARP Suppression workaround may also be considered, For more details, see DLR ARP traffic is not suppressed as expected in NSX.

Detectable by VMware SkylineTM

Actions

Copy

link to clipboard
copied!

Print

Language:
English

Attachments

Additional Resources

KB
•
End Of General Availability of the Free vSphere Hypervisor (ESXi 7.x and 8.x) (2107518)

Result 1 of 1

Ask The Community

Get answers quickly from VMware experts in the community

Post Subject

CONTINUE IN COMMUNITIES

Related Products:

VMware NSX for vSphere

Related Versions:

VMware NSX for vSphere 6.3.x

VMware NSX for vSphere 6.2.x

Take Our Survey

Support Assistant