Verify that your VMware appliance host machines to deny IPv6 neighbor solicitations unless necessary.

About this task

The dad_transmits setting determines how many neighbor solicitations to send out per address (global and link-local) when bringing up an interface to ensure the desired address is unique on the network.

Procedure

  1. Run the # grep [01] /proc/sys/net/ipv6/conf/*/dad_transmits|egrep "default|all" command on the VMware appliance host machines to confirm that they deny IPv6 neighbor solicitations.

    If the host machines are configured to deny IPv6 neighbor solicitations, this command will return values of 0.

    /proc/sys/net/ipv6/conf/all/dad_transmits:0
    /proc/sys/net/ipv6/conf/default/dad_transmits:0

    If the host machines are configured correctly, no further action is necessary.

  2. If you need to configure a host machine to deny IPv6 neighbor solicitations, open the /etc/sysctl.conf file in a text editor.
  3. Check for the following entries.
    net.ipv6.conf.all.dad_transmits=0
    net.ipv6.conf.default.dad_transmits=0

    If the entries do not exist or if their values are not set to zero, add the entries or update the existing entries accordingly.

  4. Save any changes you made and close the file.