6.5

Table Of Contents
Configure the Host System to Deny IPv6 Neighbor Solicitations
As a security best practice, verify that the host system denies IPv6 neighbor solicitations unless necessary.
The dad_transmits seing determines how many neighbor solicitations are to be sent out per address
including global and link-local, when you bring 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 to
verify whether the host system denies IPv6 neighbor solicitations.
2 If the values are not set to 0, congure the host system to deny IPv6 neighbor solicitations.
a Open the /etc/sysctl.conf le.
b If the values are not set to 0, add the following entries to the le or update the existing entries
accordingly. Set the value to 0.
net.ipv6.conf.all.dad_transmits=0
net.ipv6.conf.default.dad_transmits=0
c Save the changes and close the le.
Configure the Host System to Restrict IPv6 Maximum Addresses
As a security best practice, verify that the host restricts the maximum number of IPv6 addresses that can be
assigned. The maximum addresses seing determines how many global unicast IPv6 addresses can be
assigned to each interface. The default is 16 but you must set the number to the statically congured global
addresses required.
Procedure
1 Run the # grep [1] /proc/sys/net/ipv6/conf/*/max_addresses|egrep "default|all" command to
verify whether the host system restricts the maximum number of IPv6 addresses that can be assigned.
2 If the values are not set to 1, congure the host system to restrict the maximum number of IPv6
addresses that can be assigned.
a Open the /etc/sysctl.conf le.
b Add the following entries to the le or update the existing entries accordingly. Set the value to 1.
net.ipv6.conf.all.max_addresses=1
net.ipv6.conf.default.max_addresses=1
c Save the changes and close the le.
Configuring Ports and Protocols
As a security best practice, disable all non-essential ports and protocols.
Congure the minimum incoming and outgoing ports for vRealize Operations Manager components as
required for important system components to operate in production.
Chapter 4 Network Security and Secure Communication
VMware, Inc. 49