OpenSDN vRouter MAC Address - IP Address Learning and Bidirectional Forwarding and Detection Health Checking for Pods on Virtual Machines

date:

2020-12-11

In OpenSDN Release 2011, the OpenSDN vRouter agent dynamically learns the MAC address-IP address binding of a pod deployed on a virtual machine (VM). This enables the vRouter agent to perform an efficient pod to pod communication in OpenSDN.

In previous releases, the MAC address - IP address of a pod is assigned by OpenStack. OpenSDN is unable to perform pod to pod communication as it does not have the reachability information of the pods hosted by the VMs.

In the OpenSDN Command user interface (UI), the Dynamic Address Learning checkbox must be enabled while creating a virtual network. This enables the vRouter agent to learn the MAC address-IP address of the pods connected to the virtual network.

In release 2011, OpenSDN also supports Bidirectional Forwarding and Detection (BFD) based health check to verify the liveliness of a pod. The BFD session is enabled for a list of target IP addresses. In release 2011, OpenSDN supports IPv4 target IP addresses. The vRouter agent learns these IP addresses through the MAC address - IP address learning feature. The BFD health check session is initiated, when the vRouter agent learns the target IP address assigned to the BFD health check service. The BFD health check monitors the target list of health check for newly learnt IP addresses. If the BFD session is detected as DOWN, the vRouter agent deletes the routes generated for the MAC address - IP address of a pod learned by the vRouter.

The vRouter agent also sends address resolution protocol (ARP) packets in regular intervals to newly learnt IP addresses. The vRouter agent performs this action to check a pod’s liveliness. If a pod responds to the ARP request sent by the vRouter, the pod is considered as UP. If the pod does not respond to the ARP packets, the pod is considered as DOWN. If vRouter identifies a pod as DOWN, it deletes the routes generated for the respective MAC address-IP address of the pod.

You must perform the following steps to enable the vRouter to dynamically learn the MAC address - IP address of a pod:

  1. Navigate to Overlay > Virtual Networks page. Click Create to create a new virtual network.

    Alternatively, you can also edit the properties of an existing virtual network. To edit an existing virtual network, select a virtual network from the displayed list and click the Edit (pencil) icon.

  2. Follow the steps given Create Virtual Network to create a virtual network.

  3. In the Create Virtual Network page, select Dynamic Address Learning to enable vRouter to learn the MAC address - IP address of pods dynamically.

  4. Click Create to create a VN where the vRouter can learn the MAC address - IP address of the pods connected to the VN.

    The Virtual Networks page is displayed listing the newly created virtual network.

You must perform the following steps to enable BFD based healthcheck for the pods deployed on a VM:

  1. Navigate to Services > Health Check. Click Create to create a new BFD based health check service.

    Alternatively, you can also edit the properties of an existing virtual network. To edit an existing virtual network, select a virtual network from the displayed list and click the Edit (pencil) icon.

  2. Enter values in the Create Health Check Service page according to the guidelines provided in Table 1.

  3. Click Create.

    The Health Check tab is displayed listing the newly created health check service.

Table 1: Create Health Check Fields

Field

Description

Name

Enter a name for the health check service you are creating.

Health Check Type

Select VN IP List to run health check on the IP addresses of the virtual networks.

Protocol

Protocol is set to BFD by default when VN IP List is selected as theHealth Check Type. BFD health check enables you to verify pod liveliness.

Add all option

Select this to run BFD health check for all IP addresses learned by the vRouter Agent from learning the MAC address - IP address of a pod.

Target IP List

Select IP addresses from list to run BFD health check on the selected IP addresses.

Desired Min Tx Interval (millisecs)

Enter the desired minimum transmission (Tx) interval before transmitting BFD packets.

Required Min Rx Interval (milli secs)

Enter the minimum interval between successive BFD packets that is supported by the system.

Multiplier

Enter the number of BFD packets that must be missed successively from the remote end to declare the BFD session as DOWN.
Release History Table

Release

Description

2011

In OpenSDN Release 2011, the OpenSDN vRouter agent dynamically learns the MAC address-IP address binding of a pod deployed on a virtual machine (VM). This enables the vRouter agent to perform an efficient pod to pod communication in OpenSDN.

2011

In release 2011, OpenSDN also supports Bidirectional Forwarding and Detection (BFD) based health check to verify the liveliness of a pod.