RRAS Does Not Update the Route Table When It Receives an RIP Metric of 16

Routing and Remote Access Service (RRAS) may not properly update its routing table when it receives a Routing Information Protocol (RIP) advertisement for a route with a metric of 16. When viewing the routing table with the Kernrout Print utility, the route with the previous metric is still present. The RRAS server continues to use the old route.

This behavior can occur under the following circumstances:

• RRAS is configured to listen to RIP advertisements for normal routing.
  
  -or-
• A static route is configured as a backup route in the event that an RIP learned route becomes unavailable.

If the failed route advertisement has been modified to a metric of 16 (unreachable), RRAS should update its routing table accordingly and use the backup static route. The routing table can still show the RIP learned route at its original metric.

The following is an example of a routing table with a static route and RIP learned route to the same destination network:


When the RIP learned route becomes unreachable and is advertised as the following, the change is not reflected in the routing table:

Microsoft has confirmed that this is a problem in Windows NT 4.0.