cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
397
Views
0
Helpful
1
Replies

Easy question on prefix-list

news2010a
Level 3
Level 3

Hi, imagine I need to allow only traffic from the following networks:

10.1.0.0 /16 
10.175.206.0 255.255.255.0
10.175.207.0 255.255.255.0

between (OSPFDepartmentRouterBGP 100)--------------CorporateRouter (BGP 200)

That said, can you please give me a hint if the following prefix-lists correctly represent the networks above. I know how to get this working with route-map and access-lists but I am new to prefix-lists. Thanks!


DepartmentRouter
router bgp 100
neighbor 10.1.47.193 remote-as 200
redistribute ospf 1 route-map RM_ENG
!
ip prefix-list LIST_ENG seq 5 permit 10.0.0.0/8
ip prefix-list LIST_ENG seq 10 permit 10.175.206.0/24
ip prefix-list LIST_ENG seq 15 permit 10.175.207.0/24
!
route-map RM_ENG permit 10
match ip address prefix-list LIST_ENG
set local-preference 200
!
router ospf 1
router-id 10.1.1.15
redistribute bgp 100 metric 10 subnets route-map RM_ENG
redistribute static metric 50 metric-type 1 subnets
(...)

1 Accepted Solution

Accepted Solutions

Jerry Ye
Cisco Employee
Cisco Employee

I think you want to said to accept the routes from these networks? And you have

ip prefix-list LIST_ENG seq 5 permit 10.0.0.0/8

it should be

ip prefix-list LIST_ENG seq 5 permit 10.1.0.0/16

The end result is only the following 3 routes that will be accept to your routing table

10.1.0.0/16

10.175.206.0/24

10.175.207.0/24

If the remote is sending your a route of 10.1.1.0/24, it will be blocked.

Regards,

jerry

View solution in original post

1 Reply 1

Jerry Ye
Cisco Employee
Cisco Employee

I think you want to said to accept the routes from these networks? And you have

ip prefix-list LIST_ENG seq 5 permit 10.0.0.0/8

it should be

ip prefix-list LIST_ENG seq 5 permit 10.1.0.0/16

The end result is only the following 3 routes that will be accept to your routing table

10.1.0.0/16

10.175.206.0/24

10.175.207.0/24

If the remote is sending your a route of 10.1.1.0/24, it will be blocked.

Regards,

jerry

Getting Started

Find answers to your questions by entering keywords or phrases in the Search bar above. New here? Use these resources to familiarize yourself with the community:

Review Cisco Networking products for a $25 gift card