6.6

Table Of Contents
Configure the Host System to Deny IPv6 Router Solicitations
As a security best practice, verify that host system denies IPv6 router solicitations unless necessary. The
router solicitations seing determines how many router solicitations are sent when bringing up the
interface. If addresses are assigned statically, there is no need to send any solicitations.
Procedure
1 Run the # grep [01] /proc/sys/net/ipv6/conf/*/router_solicitations|egrep "default|all"
command to verify whether the host system denies IPv6 router solicitations unless necessary.
2 Congure the host system to deny IPv6 router solicitations.
a Open the /etc/sysctl.conf.
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.router_solicitations=0
net.ipv6.conf.default.router_solicitations=0
c Save the changes and close the le.
Configure the Host System to Deny IPv6 Router Preference in Router
Solicitations
As a security best practice, verify that your host system denies IPv6 router solicitations unless necessary. The
router preference in the solicitations seing determines router preferences. If addresses are assigned
statically, there is no need to receive any router preference for solicitations.
Procedure
1 Run the # grep [01] /proc/sys/net/ipv6/conf/*/accept_ra_rtr_pref|egrep "default|all" on the
host system to verify whether the host system denies IPv6 router solicitations.
2 Congure the host system to deny IPv6 router preference in router 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.accept_ra_rtr_pref=0
net.ipv6.conf.default.accept_ra_rtr_pref=0
c Save the changes and close the le.
Configure the Host System to Deny IPv6 Router Prefix
As a security best practice, verify that the host system denies IPv6 router prex information unless
necessary. The accept ra pinfo seing controls whether the system accepts prex information from the
router. If addresses are statically assigned, the system does not receive any router prex information.
Procedure
1 Run the # grep [01] /proc/sys/net/ipv6/conf/*/accept_ra_pinfo|egrep "default|all" to verify if
that system denies IPv6 router prex information.
Chapter 4 Network Security and Secure Communication
VMware, Inc. 45