Technical Note: How to filter incoming OSPF routes using access-list on IP address
Description
Scope
Solution
This example assumes the route to filter is 10.206.55.0/24.
Before Filter
After Filter
This article provides an example showing how to filter the incoming OSPF routes using access-list on IP address.
Scope
OSPF route filtering.
Solution
config router ospf
set abr-type cisco -> set type as ABR
config distribute-list
edit 1
set access-list "TEST" -> apply access-list
next
end
end
config router access-list
edit "TEST"
config rule
edit 1
set action deny -> set action deny to reject the route
set prefix X.X.X.X N.N.N.N -> set the route to filter
set exact-match enable -> to match exact route
next
end
next
end
This example assumes the route to filter is 10.206.55.0/24.
Before Filter
# get router info ospf database brief
Summary Link States (Area 0.0.0.0)
Link ID ADV Router Age Seq# CkSum Flag Route
10.206.55.0 10.205.240.59 790 8000013c 5426 0012 10.206.55.0/24
10.206.59.0 10.205.240.59 933 8000013c 284e 0012 10.206.59.0/24
After Filter
# get router info ospf database brief
Summary Link States (Area 0.0.0.0)
Link ID ADV Router Age Seq# CkSum Flag Route
10.206.59.0 10.205.240.59 933 8000013c 284e 0012 10.206.59.0/24
