Administration of Routing in Trusted Extensions

Trusted Extensions supports several methods for routing communications between networks. In the Security Administrator role, you can set up routes that enforce the degree of security required by your site's security policy.

For example, sites can restrict communications outside the local network to a single label. This label is applied to publicly available information. Labels such as UNCLASSIFIED or PUBLIC can indicate public information. To enforce the restriction, these sites assign a single-label template to the network interface that is connected to the external network. For more details about TCP/IP and routing, see the following:

• Planning for Routers on Your Network in System Administration Guide: IP Services

• Configuring Systems on the Local Network in System Administration Guide: IP Services

• Major TCP/IP Administrative Tasks (Task Map) in System Administration Guide: IP Services

• Preparing Your Network for the DHCP Service (Task Map) in System Administration Guide: IP Services

Choosing Routers in Trusted Extensions

Trusted Extensions hosts offer the highest degree of trust as routers. Other types of routers might not recognize Trusted Extensions security attributes. Without administrative action, packets can be routed through routers that do not provide MAC security protection.

• CIPSO routers drop packets when they do not find the correct type of information in the IP options section of the packet. For example, a CIPSO router drops a packet if it does not find a CIPSO option in the IP options when the option is required, or when the DOI in the IP options is not consistent with the destination's accreditation.

• Other types of routers that are not running Trusted Extensions software can be configured to either pass the packets or drop the packets that include the CIPSO option. Only CIPSO-aware gateways such as Trusted Extensions provides can use the contents of the CIPSO IP option to enforce MAC.

To support trusted routing, the Solaris 10 routing tables are extended to include Trusted Extensions security attributes. The attributes are described in Routing Table Entries in Trusted Extensions. Trusted Extensions supports static routing, in which the administrator creates routing table entries manually. For details, see the -p option in the route(1M) man page.

The routing software tries to find a route to the destination host in the routing tables. When the host is not explicitly named, the routing software looks for an entry for the subnetwork where the host resides. When neither the host nor the network where the host resides is defined, the host sends the packet to a default gateway, if defined. Multiple default gateways can be defined, and each is treated equally.

In this release of Trusted Extensions, the security administrator sets up routes manually, and then manually changes the routing table when conditions change. For example, many sites have a single gateway that communicates with the outside world. In these cases, the single gateway can be statically defined as the default on each host on the network. Dynamic routing support might be available in future releases of Trusted Extensions.

Gateways in Trusted Extensions

An example of routing in Trusted Extensions follows. The diagram and table show three potential routes between Host 1 and Host 2.

Figure 12-1 Typical Trusted Extensions Routes and Routing Table Entries

• Route #1 can transmit packets within the label range of CONFIDENTIAL to SECRET.

• Route #2 can transmit packets from ADMIN_LOW to ADMIN_HIGH.

• Route #3 does not specify routing information. Therefore, its security attributes are derived from the template in the tnrhtp database for Gateway 5.

Routing Commands in Trusted Extensions

To show labels and extended security attributes for sockets, Trusted Extensions modifies the following Oracle Solaris network commands:

• The netstat -rR command displays the security attributes in routing table entries.

• The netstat -aR command displays the security attributes for sockets.

• The route -p command with the add or delete option changes the routing table entries.

For details, see the netstat(1M) and route(1M) man pages.

For examples, see How to Configure Routes With Security Attributes.