Enabling Routing for Single-Interface Systems

You can configure single-interface systems with either static or dynamic routing. With static routing, the host must rely upon the services of a default router for routing information. Enabling dynamic routing that uses a routing protocol is the easiest way to manage routing on a system.

Sites with multiple routers and networks typically administer their network topology as a single routing domain or an autonomous system (AS). The procedures and examples in this section are based on the following figure. In this figure, an AS is divided into three local networks: 10.0.5.0, 172.20.1.0, and 192.168.5.0. The network is comprised of routers and client systems, including the following types of routers: border routers, default routers, and packet-forwarding routers. Client systems include multihomed systems and single-interface systems. For more details about each of these components, see IPv4 Autonomous System Topology in Planning for Network Deployment in Oracle Solaris 11.2 .

Figure 3-1  Autonomous System With Multiple IPv4 Routers

How to Enable Dynamic Routing on a Single-Interface System

The following procedure assumes that you have already configured the system's IP interface. For more details about planning for routers on a network, see IPv4 Autonomous System Topology in Planning for Network Deployment in Oracle Solaris 11.2 .

1. Become an administrator.
2. Configure one of the system's IP interfaces with an IP address for the network to which the system belongs.

   For instructions, see How to Configure an IPv4 Interface.

3. Delete all of the persistently defined routes from the system.

   You perform this step because the presence of any statically defined default routes prevents the system from enabling dynamic routing during a system boot.

   1. Determine all of the persistently defined default routes as follows:

      # route -p show

   2. Delete each of the persistently defined routes. For example:

   # route -p delete -net default -gateway 172.20.1.10

4. Ensure that packet forwarding is disabled.

   # routeadm -d ipv4-forwarding -u

5. Enable IPv4 routing on the system.

   # routeadm -e ipv4-routing -u

Example 3-8  Running Dynamic Routing on a Single-Interface System

The following example shows how to configure dynamic routing for hosta, which is a single-interface system on the network 192.168.5.0, as illustrated in Figure 3–1. The system uses Router 1 as its default router. The example assumes that you have already configured the system's IP interface.

First, you would log into hosta with administrator rights. Then, you would remove all of the persistently defined routes from the system.

# route -p show
persistent: route add default 172.20.1.10

# route -p delete default 172.20.1.10
delete net default: gateway 172.20.1.10
delete persistent net default: gateway 172.20.1.10

# routeadm 
              Configuration   Current              Current
                     Option   Configuration        System State
---------------------------------------------------------------
               IPv4 routing   disabled             disabled
               IPv6 routing   disabled             disabled
            IPv4 forwarding   disabled             disabled
            IPv6 forwarding   disabled             disabled

           Routing services   "route:default ripng:default"

Routing daemons:

                      STATE   FMRI
                   disabled   svc:/network/routing/ripng:default
                     online   svc:/network/routing/ndp:default
                   disabled   svc:/network/routing/rdisc:default
                   disabled   svc:/network/routing/legacy-routing:ipv4
                   disabled   svc:/network/routing/legacy-routing:ipv6
                   disabled   svc:/network/routing/route:default

# routeadm -d ipv4-forwarding -u
# routeadm -e ipv4-routing -u
# routeadm
              Configuration   Current              Current
                     Option   Configuration        System State
---------------------------------------------------------------
               IPv4 routing   enabled              enabled
               IPv6 routing   disabled             disabled
            IPv4 forwarding   disabled             disabled
            IPv6 forwarding   disabled             disabled

           Routing services   "route:default ripng:default"

Routing daemons:

                      STATE   FMRI
                   disabled   svc:/network/routing/ripng:default
                     online   svc:/network/routing/ndp:default
                   disabled   svc:/network/routing/rdisc:default
                   disabled   svc:/network/routing/legacy-routing:ipv4
                   disabled   svc:/network/routing/legacy-routing:ipv6
                     online   svc:/network/routing/route:default