6.6

Table Of Contents
Configure NTP on VMware Appliances
For critical time sourcing, disable host time synchronization and use the Network Time Protocol (NTP) on
VMware appliances. You must congure a trusted remote NTP server for time synchronization. The NTP
server must be an authoritative time server or at least synchronized with an authoritative time server.
The NTP daemon on VMware virtual appliances provides synchronized time services. NTP is disabled by
default, so you need to congure it manually. If possible, use NTP in production environments to track user
actions and to detect potential malicious aacks and intrusions through accurate audit and log keeping. For
information about NTP security notices, see the NTP Web site.
The NTP conguration le is located in the /etc/ntp.conf le on each appliance.
Procedure
1 Navigate to the /etc/ntp.conf conguration le on your virtual appliance host machine.
2 Set the le ownership to root:root.
3 Set the permissions to 0640.
4 To mitigate the risk of a denial-of-service amplication aack on the NTP service, open
the /etc/ntp.conf le and ensure that the restrict lines appear in the le.
restrict default kod nomodify notrap nopeer noquery
restrict -6 default kod nomodify notrap nopeer noquery
restrict 127.0.0.1
restrict -6 ::1
5 Save any changes and close the les.
For information on NTP security notices, see hp://support.ntp.org/bin/view/Main/SecurityNotice.
Disable the TCP Timestamp Response on Linux
Use the TCP timestamp response to approximate the remote host's uptime and aid in further aacks.
Additionally, some operating systems can be ngerprinted based on the behavior of their TCP time stamps.
Procedure
u
Disable the TCP timestamp response on Linux.
a To set the value of net.ipv4.tcp_timestamps to 0, run the sysctl -w net.ipv4.tcp_timestamps=0
command.
b Add the ipv4.tcp_timestamps=0 value in the default sysctl.conf le.
Enable FIPS 140-2 Mode
The version of OpenSSL that is shipped with vRealize Operations Manager 6.3 and later releases is FIPS
140-2 certied. However, the FIPS mode is not enabled by default.
You can enable the FIPS mode if there is a security compliance requirement to use FIPS certied
cryptographic algorithms with the FIPS mode enabled.
Procedure
1 To replace the mod_ssl.so le run the following command:
cd /usr/lib64/apache2-prefork/
cp mod_ssl.so mod_ssl.so.old
cp mod_ssl.so.FIPSON.openssl1.0.2 mod_ssl.so
Secure Configuration
20 VMware, Inc.