Configuration using the Domain Name Service (DNS)

The domain name service (DNS) is the accepted Internet standard naming service for the resolution of hostnames and IP addresses. To use DNS in combination with Solstice PPP, you must specify your name servers and enable DNS as your naming service. Consider the previous example configuration, as shown in Figure 5-8.

Figure 5-8 Using the Domain Name Service (DNS)

Configuring the Client

On the client, create the file /etc/resolv.conf that contains the domain name and the IP addresses of all the name servers. For example:

domain	xyz.Company.COM
nameserver	179.xxx.zzz.11
nameserver	...
nameserver	...

To use DNS as the default naming service, edit the file /etc/nsswitch.conf and edit the hosts entry as follows:

hosts:   files dns 

The changes are implemented automatically. You do not need to reboot the machine.

To be certain that you can resolve all IP addresses over the PPP link, use the default_route keyword in the dialup path definition for the connection to the router. This adds the route to the route table as the default destination. The route is removed when the IP interface is marked down.

Configuring the Router

The router does not have to use DNS as its naming service, but it may do so. On the router, the IP interface for the PPP link may be configured up or down.

If the interface is up, the IP routing is configured when the machine is rebooted. The file /etc/gateways must exist on the router, so that it advertises itself to the rest of the network as a gateway.

If the interface is down, you must configure the routing manually, as follows:

1. Set the ip_forwarding flag.

   prompt# ndd -set /dev/ip_forwarding 1

2. Add a passive route to the remote host in the routing table.

   prompt# route add host remote_host_addr router_addr 1

   To add the route for the remote host in the example, type:

   prompt# route add host 179.xxx.zzz.117 179.xxx.yyy.10 1

   Alternatively, you can use a different routing mechanism, such as gated, to configure the IP routing for Solstice PPP.