Managing RIP

After the demand-dial or LAN interfaces have been created, configuring the appropriate routing protocol interfaces is the last step in configuring the RRAS server as a network router. You must first add the routing protocol by rightclicking the General node and choosing New Routing Protocol. The window that appears lists the protocols from which you can choose. Select RIPv2 and click OK.

After the routing protocol has been added, you must add the interfaces. To do so, right-click the appropriate routing protocol and select New Interface. After you select an interface and click OK, the Properties window for the interface appears, enabling you to configure it.

Every RIP interface has it own Properties window from which you can configure a number of options. Within the RRAS console, expand IP Routing, RIP; and then right-click one of the available interfaces and click Properties.

The General tab enables you to configure the operation mode. You can select either Autostatic Update Mode or Periodic Update Mode. With autostatic update, RIP announcements are sent when other routers request updates. Any routes learned while in autostatic update mode are marked as static and remain in the routing table until the administrator manually deletes them. In periodic update mode, announcements are sent out periodically. (The Periodic Announcement Interval determines how often.) These routes are automatically deleted when the router is stopped and restarted. The outgoing and incoming packet protocol enables you to configure the type of packets, such as RIPv1 or RIPv2, the router sends and accepts.

The Activate Authentication and Password options enable you to maintain an added level of security. If authentication is enabled, all outgoing and incoming packets must contain the password specified in the password field. When using authentication, make sure that all neighboring routers are configured with an identical password.

From the Security tab, an administrator can configure RIP route filters. The router can be configured to send and accept all routes, send and accept only routes from the ranges specified, or accept and send all routes except for those specified.

The Neighbors tab is used to configure how the router interacts with other RIP routers. The Advanced tab has several configurable options:

• Periodic Announcement Interval: Controls the interval at which periodic update announcements are made.
• Time Before Route Expires: Determines how long a route remains in the routing table before it expires.
• Time Before Route Is Removed: Determines how long an expired route remains in the routing table before being removed.
• Enable Split Horizon Processing: Ensures that routing loops do not occur because the routes learned from a router are not rebroadcast to that network.
• Enable Triggered Updates: Controls whether changes in the routing table are sent out immediately.
• Send Clean-Up Updates when Stopped: Controls whether the router sends an announcement when it is stopped to notify other routers that the routes for which it was responsible are no longer available.
• Process Host Routes in Received Announcements: Controls whether host routes received in RIP announcements are accepted or denied.
• Include Host Routes in Send Announcements: Controls whether host routes are included in RIP announcements.
• Process Default Routes in Received Announcements: Controls whether default routes received in RIP announcements are accepted or denied.
• Process Default Routes in Send Announcements: Controls whether default routes are included in RIP announcements.
• Disable Subnet Summarization: This option is available only for RIPv2. It controls whether subnets are advertised to routers on different subnets.

When a routing loop occurs, packets bounce back and forth between routers. When split-horizon processing is enabled, routes are not advertised back to the router from which they are learned. For example, if RouterB receives advertised routes from RouterA, RouterB does not advertise these routes back to RouterA. When Split Horizon with Poison Reverse is enabled, routes are advertised back to the router from which they were learned with a hop count of infinity.