About OSPF Redistribution

 关于从其他路由进程重分发入OSPF进程的路由：

1 Type: Routes are redistributed in OSPF as either type 1 (E1) routes or type 2 (E2) routes, with type 2 being the default

2 Metric: The default cost or metric of a redistributed route is 1 for BGP and 20 for all other protocols 

3 Tag: A 32-bit value that is attached to the redistributed routes. The route tag is not used by OSPF but can be referenced in a route map for making policy decisions. One possible use is to base the decision to redistribute a route based on the route tag. The default tag value is 0. The range of values for the tag is 0–4,294,967,295

4  if the subnets keyword is not used，it will redistribute classful routes into OSPF

5  A type 1 route has a metric that is the sum of the internal OSPF cost and the external redistributed cost.配置命令为redistribute eigrp 1 metric 66 metric-type 1. 这样既指定了作为Type几的路由注入，也指定了metric

6 总结一下，default的情况就是

Remember the defaults: metric = 20 (1 for BGP), metric type = 2, tag = 0.