Configure Route Filtering with Redistribution

topology

Task 1 Link to heading

Configure basic EIGRP and OSPF

Configuration Link to heading

hostname RD1
int f0/0
    no shut
    ip add 172.16.18.1 255.255.255.252
int f0/1
    no shut
    ip add 172.16.14.1 255.255.255.252
int f1/0
    no shut
    ip add 172.30.12.1 255.255.255.252
router eigrp 1
    no auto-summary
    net 172.30.12.0 0.0.0.3
    redistribute ospf 100
    default-metric 1500 10 255 1 1500
router ospf 100
    net 172.16.18.0 0.0.0.3 area 0
    net 172.16.14.0 0.0.0.3 area 0
    redistribute eigrp 1 subnets

hostname R2
int f0/0
    no shut
    ip add 172.30.12.2 255.255.255.252
int f0/1
    no shut
    ip add 172.30.2.1 255.255.255.128
router eigrp 1
    no auto-summary
    net 172.30.12.0 0.0.0.3
    net 172.30.2.0 0.0.0.127
    passive-interface f0/1

hostname R4
int f0/0
    no shut
    ip add 172.16.14.2 255.255.255.252
int f0/1
    no shut
    ip add 172.16.4.1 255.255.255.128
int f1/0
    no shut
int f1/0.101
    encapsulation dot1Q 101
    ip add 172.16.101.1 255.255.255.0
int f1/0.102
    encapsulation dot1Q 102
    ip add 172.16.102.1 255.255.255.128
int f1/0.103
    encapsulation dot1Q 103
    ip add 172.16.103.1 255.255.255.192
int f1/0.104
    encapsulation dot1Q 104
    ip add 172.16.104.1 255.255.255.224
int f1/0.105
    encapsulation dot1Q 105
    ip add 172.16.105.1 255.255.255.240
int f1/0.106
    encapsulation dot1Q 106
    ip add 172.16.106.1 255.255.255.248
int f1/0.107
    encapsulation dot1Q 107
    ip add 172.16.107.1 255.255.255.252
router ospf 100
    net 172.16.14.0 0.0.0.3 area 0
    net 172.16.4.0 0.0.0.127 area 0
    net 172.16.101.0 0.0.0.255 area 3
    net 172.16.102.0 0.0.0.127 area 3
    net 172.16.103.0 0.0.0.63 area 3
    net 172.16.104.0 0.0.0.31 area 3
    net 172.16.105.0 0.0.0.15 area 3
    net 172.16.106.0 0.0.0.7 area 3
    net 172.16.107.0 0.0.0.3 area 3
    passive-interface f0/1
    passive-interface f1/0

hostname R8
int f0/0
    no shut
    ip add 172.16.18.2 255.255.255.252
int f0/1
    no shut
    ip add 172.16.8.1 255.255.255.128
router ospf 100
    net 172.16.18.0 0.0.0.3 area 0
    net 172.16.8.0 0.0.0.127 area 0
    passive-interface f0/1

Verification Link to heading

R2# show ip route eigrp
Codes: D - EIGRP, EX - EIGRP external
Gateway of last resort is not set
      172.16.0.0/16 is variably subnetted, 11 subnets, 7 masks
D EX     172.16.4.0/25
           [170/1711616] via 172.30.12.1, 00:02:47, FastEthernet0/0
D EX     172.16.8.0/25
           [170/1711616] via 172.30.12.1, 00:03:26, FastEthernet0/0
D EX     172.16.14.0/30
           [170/1711616] via 172.30.12.1, 00:03:26, FastEthernet0/0
D EX     172.16.18.0/30
           [170/1711616] via 172.30.12.1, 00:03:26, FastEthernet0/0
D EX     172.16.101.0/24
           [170/1711616] via 172.30.12.1, 00:00:42, FastEthernet0/0
D EX     172.16.102.0/25
           [170/1711616] via 172.30.12.1, 00:00:42, FastEthernet0/0
D EX     172.16.103.0/26
           [170/1711616] via 172.30.12.1, 00:00:42, FastEthernet0/0
D EX     172.16.104.0/27
           [170/1711616] via 172.30.12.1, 00:00:42, FastEthernet0/0
D EX     172.16.105.0/28
           [170/1711616] via 172.30.12.1, 00:00:42, FastEthernet0/0
D EX     172.16.106.0/29
           [170/1711616] via 172.30.12.1, 00:00:42, FastEthernet0/0
D EX     172.16.107.0/30
           [170/1711616] via 172.30.12.1, 00:00:42, FastEthernet0/0

table

Task 2 Link to heading

Configure RD1 to filter routes from Area 3 to EIGRP.
Using extended ACLs to match denied routes.

Configuration Link to heading

These following ACLs are used for routes filtering, so the syntax will be host <network> host <subnet mask>, instead of <source address> <destination address>

RD1(config)#
# ACLs matches network 101
ip access-list extended match-101
    permit ip host 172.16.101.0 host 255.255.255.0
# ACLs matches network 104 and 105
ip access-list extended match-104-105
    permit ip host 172.16.104.0 host 255.255.255.224
    permit ip host 172.16.105.0 host 255.255.255.240
# Filter network 101
route-map option1 deny 10
    match ip address match-101
# Filter network 104 and 105
route-map option1 deny 20
    match ip address match-104-105
# Permit other networks
route-map option1 permit 30
router eigrp 1
    redistribute ospf 100 route-map option1

Verification Link to heading

R2# show ip route eigrp
Codes: D - EIGRP, EX - EIGRP external
Gateway of last resort is not set
      172.16.0.0/16 is variably subnetted, 8 subnets, 4 masks
D EX     172.16.4.0/25
           [170/1711616] via 172.30.12.1, 00:11:42, FastEthernet0/0
D EX     172.16.8.0/25
           [170/1711616] via 172.30.12.1, 00:12:21, FastEthernet0/0
D EX     172.16.14.0/30
           [170/1711616] via 172.30.12.1, 00:12:21, FastEthernet0/0
D EX     172.16.18.0/30
           [170/1711616] via 172.30.12.1, 00:12:21, FastEthernet0/0
D EX     172.16.102.0/25
           [170/1711616] via 172.30.12.1, 00:09:37, FastEthernet0/0
D EX     172.16.103.0/26
           [170/1711616] via 172.30.12.1, 00:09:37, FastEthernet0/0
D EX     172.16.106.0/29
           [170/1711616] via 172.30.12.1, 00:09:37, FastEthernet0/0
D EX     172.16.107.0/30
           [170/1711616] via 172.30.12.1, 00:09:37, FastEthernet0/0

Task 3 Link to heading

Configure RD1 to filter routes from Area 3 to EIGRP.
Using prefix-list to match permited routes.

Configuration Link to heading

# Prefix-list match permited networks
ip prefix-list match-area0-permit permit 172.16.14.0/30
ip prefix-list match-area0-permit permit 172.16.18.0/30
ip prefix-list match-area0-permit permit 172.16.8.0/25
ip prefix-list match-area0-permit permit 172.16.4.0/25
ip prefix-list match-area3-permit permit 172.16.102.0/23 ge 25 le 26
ip prefix-list match-area3-permit permit 172.16.106.0/23 ge 29 le 30
# Permit networks
route-map option2 permit 10
match ip address prefix-list match-area3-permit
route-map option2 permit 10
match ip address prefix-list match-area0-permit
router eigrp 1
redistribute ospf 100 route-map option2

Verification Link to heading

R2#show ip route eigrp
Codes: D - EIGRP, EX - EIGRP external
Gateway of last resort is not set
      172.16.0.0/16 is variably subnetted, 8 subnets, 4 masks
D EX     172.16.4.0/25
           [170/1711616] via 172.30.12.1, 00:00:07, FastEthernet0/0
D EX     172.16.8.0/25
           [170/1711616] via 172.30.12.1, 00:00:07, FastEthernet0/0
D EX     172.16.14.0/30
           [170/1711616] via 172.30.12.1, 00:00:07, FastEthernet0/0
D EX     172.16.18.0/30
           [170/1711616] via 172.30.12.1, 00:00:07, FastEthernet0/0
D EX     172.16.102.0/25
           [170/1711616] via 172.30.12.1, 00:00:07, FastEthernet0/0
D EX     172.16.103.0/26
           [170/1711616] via 172.30.12.1, 00:00:07, FastEthernet0/0
D EX     172.16.106.0/29
           [170/1711616] via 172.30.12.1, 00:00:07, FastEthernet0/0
D EX     172.16.107.0/30
           [170/1711616] via 172.30.12.1, 00:00:07, FastEthernet0/0