HP UX IPSec Software Chapter, Bypass List, Maximizing Security, Maximizing Security, Strong End System Model

Configuring HP-UX IPSec

Maximizing SecurityMaximizing Security

A system may have both “public” interface IP addresses and “private” interface IP addresses. A public interface IP address is an IP address configured on a Network Interface Card (NIC) connected to a public network. A private interface IP address is an IP address configured on a NIC connected to a private internal network. If you have a system with both a public interface IP address and a private interface IP address, do not assume that all packets processed by the private interface originated from the private network. Do not configure any “open” IPSec policies that allow most or all packets sent to the private interface IP address to pass in clear text.

If you configure an open IPSec policy for a private interface IP address on a system that also has public interfaces, intruders may be able to access services or ports bound to the private interface IP address from other NICs on the system, even if the other interface IP addresses are secured by IPSec policies. Intruders may access services or ports bound to the private interface IP address, even if the intruders are not directly connected to the private interface.

Bypass List

Configuring an entry in the bypass list has the same effect as configuring an open IPSec policy, so the same conditions exist. Intruders may be able to access services or ports bound to the address in the bypass list from other interfaces on the system, even if the other interfaces are secured by IPSec policies. Intruders may access services or ports bound to the address in the bypass list even if the intruders are not directly connected to the interface in the bypass list.

HP recommends that you do not configure open IPSec policies, or entries in the bypass list for private interfaces on systems that also have public interfaces, or on systems on which you are using HP-UX IPSec as a filter or firewall to protect your network.

Strong End System Model

To maximize security when using open policies or the bypass list, HP recommends that you enable the RFC 1122 Strong End-System Model. You can do this by entering the following command:

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