Redistribution issue between two routing protocol

Publication Date:  2016-12-29 Views:  613 Downloads:  0
Issue Description

There is redistribution issue between two routing protocol. For OSPF, administrative distance of internal OSPF
route is 10. But the administrative distance of external OSPF route is 150. The
administrative distance of ISIS is 15. Customer found that there is packet loss
and sometimes network unreachable from ISIS network to OSPF external route


In this case, customer only performs simple redistribution without any
route protection feature. Suboptimal route occurred which resulted in network

To improve this situation, we use filter policy to filter the OSPF
external route at another switch in ISIS.

Two switch configuration:


Filter-policy ip-prefix filter import

Ip ip-prefix filter deny 24

Ip ip-prefix filter permit 0 less-equal 32