14-6 redistribute routing-process process-id route-map route-map-name

14-6 redistribute routing-process process-id route-map route-map- name

Syntax Description:

• routing-process ” Routing process to redistribute into OSPF. The routing process can be BGP, Connected, EGP, EIGRP, IGRP, ISIS, ISO-IGRP, Mobile, ODR, OSPF, RIP, or Static.

• process-id ” The process ID of the routing process (if applicable ).

• route-map-name ” Name of the route map used to control which routes are redistributed or to set the parameters of the redistributed routes (metric, metric-type, or tag).

Purpose: To control the redistribution of routes learned from another routing process into OSPF. Redistributed routes become OSPF external type 2 routes by default. The default cost or metric of a redistributed route is 1 for BGP and 20 for all other protocols. This command will redistribute classful routes into OSPF only if the subnets keyword is not used. There are three general types of classful routes:

• A Class A address with an 8-bit mask

• A Class B address with a 16-bit mask

• A Class C address with a 24-bit mask

You can use the subnets keyword to redistribute all routes. You can also use the metric, metric-type, and tag keywords. These values can also be set in the route map as shown in the examples covered in this section.

Initial Cisco IOS Software Release: 10.0

Configuration Example: 1 Controlling the Routes to Be Redistributed Based on IP Address

In Figure 14-3, Router B is receiving six routes from Router C via EIGRP. Three of the EIGRP routes are classful (5.0.0.0/8, 145.5.0.0/16, 205.5.5.0/24) and three are classless (6.0.0.0/12, 146.6.0.0/20, 206.6.6.0/28). For this example, only the classless routes will be redistributed. Before redistributing the EIGRP routes into OSPF on Router B, configure the routers as shown in the listing that follows .

Figure 14-3. A Route Map Is Needed to Control Which Routes Are Redistributed into OSPF from EIGRP

 Router A  interface Loopback0   ip address 1.1.1.1 255.255.255.255   !   interface Serial0/1   ip address 10.1.1.1 255.255.255.252   clockrate 64000   !   router ospf 1   network 10.1.1.0 0.0.0.3 area 0  _______________________________________________________________________ Router B  interface Loopback0   ip address 2.2.2.2 255.255.255.255   !   interface Serial0   ip address 10.1.1.2 255.255.255.252   !   interface Serial 1   ip address 10.1.1.5 255.255.255.252   !   router eigrp 1   network 10.0.0.0   !   router ospf 1   network 10.1.1.0 0.0.0.3 area 0  _______________________________________________________________________ Router C  interface Loopback0   ip address 3.3.3.3 255.255.255.255   !   interface Loopback1   ip address 5.5.5.5 255.0.0.0   !   interface Loopback2   ip address 6.6.6.6 255.240.0.0   !   interface Loopback3   ip address 145.5.5.5 255.255.0.0   !   interface Loopback4   ip address 146.6.6.6 255.255.240.0   !   interface Loopback5   ip address 205.5.5.5 255.255.255.0   !   interface Loopback6   ip address 206.6.6.6 255.255.255.240   !   interface Serial0   ip address 10.1.1.6 255.255.255.252   !   router eigrp 1   network 5.0.0.0   network 6.0.0.0   network 10.0.0.0   network 145.5.0.0   network 146.6.0.0   network 205.5.5.0   network 206.6.6.0   no auto-summary  

Verify that Routers A and B have established an OSPF neighbor relationship.

 rtrA#  show ip ospf neighbor  Neighbor ID     Pri   State           Dead Time   Address         Interface 2.2.2.2           1  FULL/  -  00:00:36    10.1.1.2        Serial0/1 

Verify that Routers B and C have formed an EIGRP neighbor relationship.

 rtrB#  show ip eigrp neighbors  IP-EIGRP neighbors for process 1 H   Address                 Interface   Hold  Uptime  SRTT   RTO  Q  Seq                                         (sec)         (ms)       Cnt Num 0   10.1.1.6                Se1           11  00:25:42  308  2280  0  4 

Verify that Router B is receiving the six EIGRP routes from Router C.

 rtrB#  show ip route  Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP  D - EIGRP  , EX - EIGRP external, O - OSPF, IA - OSPF inter area        N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2        E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP        i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, * - candidate default        U - per-user static route, o - ODR Gateway of last resort is not set      2.0.0.0/32 is subnetted, 1 subnets C       2.2.2.2 is directly connected, Loopback0  D    205.5.5.0/24 [90/40640000] via 10.1.1.6, 00:26:25, Serial1  206.6.6.0/28 is subnetted, 1 subnets  D       206.6.6.0 [90/40640000] via 10.1.1.6, 00:26:25, Serial1   D    5.0.0.0/8 [90/40640000] via 10.1.1.6, 00:26:25, Serial1  6.0.0.0/12 is subnetted, 1 subnets  D       6.0.0.0 [90/40640000] via 10.1.1.6, 00:26:25, Serial1   D    145.5.0.0/16 [90/40640000] via 10.1.1.6, 00:26:25, Serial1  10.0.0.0/30 is subnetted, 2 subnets C       10.1.1.0 is directly connected, Serial0 C       10.1.1.4 is directly connected, Serial1      146.6.0.0/20 is subnetted, 1 subnets  D       146.6.0.0 [90/40640000] via 10.1.1.6, 00:26:27, Serial1  

Modify the configuration on Router B to redistribute only the classless EIGRP routes into OSPF.

 Router B  router ospf 1     redistribute eigrp 1 subnets route-map control-eigrp    !    access-list 1 permit 6.0.0.0 0.15.255.255     access-list 1 permit 146.6.0.0 0.0.15.255     access-list 1 permit 206.6.6.0 0.0.0.15     access-list 1 permit 10.1.1.4 0.0.0.3     route-map control-eigrp permit 10      match ip address 1   

Verification

Verify that only the classless EIGRP routes have been redistributed into OSPF.

 rtrA#  show ip route  Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP        D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area        N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2        E1 - OSPF external type 1,  E2 - OSPF external type 2  , E - EGP        i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter area        * - candidate default, U - per-user static route, o - ODR        P - periodic downloaded static route Gateway of last resort is not set      1.0.0.0/32 is subnetted, 1 subnets C       1.1.1.1 is directly connected, Loopback0      206.6.6.0/28 is subnetted, 1 subnets  O E2    206.6.6.0 [110/20] via 10.1.1.2, 00:02:05, Serial0/1  6.0.0.0/12 is subnetted, 1 subnets  O E2    6.0.0.0 [110/20] via 10.1.1.2, 00:02:05, Serial0/1  10.0.0.0/30 is subnetted, 1 subnets C       10.1.1.0 is directly connected, Serial0/1      146.6.0.0/20 is subnetted, 1 subnets  O E2    146.6.0.0 [110/20] via 10.1.1.2, 00:02:06, Serial0/1   O E2    10.1.1.4 [110/200] via 10.1.1.2, 00:02:06, Serial0/1  

Configuration Example: 2 Modifying the Metric of Redistributed Routes Using a Route Map

In the first configuration example for Figure 14-3, the EIGRP routes were redistributed into OSPF with a default metric of 20. For this example, modify the configuration on Router B to change the metric of the classful routes to 100 and the metric of the classless routes to 200.

 Router B  router ospf 1   redistribute eigrp 1 subnets route-map control-eigrp   !   access-list 1 permit 6.0.0.0 0.15.255.255   access-list 1 permit 146.6.0.0 0.0.15.255   access-list 1 permit 206.6.6.0 0.0.0.15   access-list 1 permit 10.1.1.4 0.0.0.3   route-map control-eigrp permit 10   match ip address 1     set metric 200     !     route-map control-eigrp permit 20      set metric 100   

Verification

Verify that the new metric has been applied to the redistributed EIGRP routes. On Router A you can look at the IP routing table and the OSPF database.

 rtrA#  show ip route  Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP        D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area        N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2        E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP        i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter area        * - candidate default, U - per-user static route, o - ODR        P - periodic downloaded static route Gateway of last resort is not set      1.0.0.0/32 is subnetted, 1 subnets C       1.1.1.1 is directly connected, Loopback0 O E2 205.5.5.0/24 [110/  100  ] via 10.1.1.2, 00:01:53, Serial0/1      206.6.6.0/28 is subnetted, 1 subnets O E2    206.6.6.0 [110/  200  ] via 10.1.1.2, 00:01:53, Serial0/1 O E2 5.0.0.0/8 [110/  100  ] via 10.1.1.2, 00:01:53, Serial0/1      6.0.0.0/12 is subnetted, 1 subnets O E2    6.0.0.0 [110/  200  ] via 10.1.1.2, 00:01:53, Serial0/1      172.16.0.0/24 is subnetted, 1 subnets C       172.16.1.0 is directly connected, Ethernet0/0 O E2 145.5.0.0/16 [110/  100  ] via 10.1.1.2, 00:01:54, Serial0/1      10.0.0.0/30 is subnetted, 2 subnets C       10.1.1.0 is directly connected, Serial0/1 O E2    10.1.1.4 [110/  200  ] via 10.1.1.2, 00:01:55, Serial0/1      146.6.0.0/20 is subnetted, 1 subnets O E2    146.6.0.0 [110/  200  ] via 10.1.1.2, 00:01:55, Serial0/1 rtrA#  show ip ospf database external 5.0.0.0  OSPF Router with ID (1.1.1.1) (Process ID 1)                 Type-5 AS External Link States   Routing Bit Set on this LSA   LS age: 254   Options: (No TOS-capability, DC)   LS Type: AS External Link   Link State ID: 5.0.0.0 (External Network Number )   Advertising Router: 2.2.2.2   LS Seq Number: 80000002   Checksum: 0x8BB6   Length: 36   Network Mask: /8         Metric Type: 2 (Larger than any link state path)         TOS: 0  Metric: 100  Forward Address: 0.0.0.0         External Route Tag: 0 rtrA#  show ip ospf database external 206.6.6.0  OSPF Router with ID (1.1.1.1) (Process ID 1)                 Type-5 AS External Link States   Routing Bit Set on this LSA   LS age: 297   Options: (No TOS-capability, DC)   LS Type: AS External Link   Link State ID: 206.6.6.0 (External Network Number )   Advertising Router: 2.2.2.2   LS Seq Number: 80000003   Checksum: 0x51C4   Length: 36   Network Mask: /28         Metric Type: 2 (Larger than any link state path)         TOS: 0  Metric: 200  Forward Address: 0.0.0.0         External Route Tag: 0 

Configuration Example: 3 Modifying the Metric Type of Redistributed Routes Using a Route Map

In Figure 14-3, configuration example 1 for the redistribute route-map command, the EIGRP routes were redistributed into OSPF with a default metric type of 2. For this example, modify the configuration on Router B to change the metric type of the classful routes to type 1.

 Router B  router ospf 1   redistribute eigrp 1 subnets route-map control-eigrp   network 10.1.1.0 0.0.0.3 area 0   !   access-list 1 permit 6.0.0.0 0.15.255.255   access-list 1 permit 146.6.0.0 0.0.15.255   access-list 1 permit 206.6.6.0 0.0.0.15   access-list 1 permit   route-map control-eigrp permit 10   match ip address 1   set metric 200   !   route-map control-eigrp permit 20   set metric 100     set metric-type type-1   

Verification

Verify that the classful EIGRP routes have been redistributed into OSPF as metric type 1 routes.

 rtrA#  show ip route  Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP        D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area        N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2        E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP        i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter area        * - candidate default, U - per-user static route, o - ODR        P - periodic downloaded static route Gateway of last resort is not set      1.0.0.0/32 is subnetted, 1 subnets C       1.1.1.1 is directly connected, Loopback0  O E1 205.5.5.0/24 [110/1662] via 10.1.1.2, 00:01:38, Serial0/1  206.6.6.0/28 is subnetted, 1 subnets O E2    206.6.6.0 [110/200] via 10.1.1.2, 00:01:38, Serial0/1  O E1 5.0.0.0/8 [110/1662] via 10.1.1.2, 00:01:38, Serial0/1  6.0.0.0/12 is subnetted, 1 subnets O E2    6.0.0.0 [110/200] via 10.1.1.2, 00:01:38, Serial0/1      172.16.0.0/24 is subnetted, 1 subnets C       172.16.1.0 is directly connected, Ethernet0/0  O E1 145.5.0.0/16 [110/1662] via 10.1.1.2, 00:01:39, Serial0/1  10.0.0.0/30 is subnetted, 2 subnets C       10.1.1.0 is directly connected, Serial0/1 O E2    10.1.1.4 [110/  200  ] via 10.1.1.2, 00:01:41, Serial0/1      146.6.0.0/20 is subnetted, 1 subnets O E2    146.6.0.0 [110/  200  ] via 10.1.1.2, 00:01:41, Serial0/1 

Configuration Example: 4 Modifying the Tag Value of Redistributed Routes Using a Route Map

Modify the configuration on Router B (see Figure 14-3) to set the tag value for the classless routes to 1 and the classful routes to 2.

 Router B  router ospf 1   redistribute eigrp 1 subnets route-map control-eigrp   network 10.1.1.0 0.0.0.3 area 0   !   access-list 1 permit 6.0.0.0 0.15.255.255   access-list 1 permit 146.6.0.0 0.0.15.255   access-list 1 permit 206.6.6.0 0.0.0.15   access-list 1 permit 10.1.1.4 0.0.0.3   route-map control-eigrp permit 10   match ip address 1   set metric 200     set tag 1    !   route-map control-eigrp permit 20   set metric 100   set metric-type type-1     set tag 2   

Verification

Verify that the tags have been set on the redistributed EIGRP routes.

 rtrB#  show ip ospf database external 5.0.0.0  OSPF Router with ID (2.2.2.2) (Process ID 1)                 Type-5 AS External Link States   LS age: 164   Options: (No TOS-capability, DC)   LS Type: AS External Link   Link State ID: 5.0.0.0 (External Network Number )   Advertising Router: 2.2.2.2   LS Seq Number: 80000007   Checksum: 0x2299   Length: 36   Network Mask: /8         Metric Type: 1 (Comparable directly to link state metric)         TOS: 0         Metric: 100         Forward Address: 0.0.0.0  External Route Tag: 2  _______________________________________________________________________ rtrA#  show ip route 206.6.6.0 255.255.255.240  Routing entry for 206.6.6.0/28   Known via "ospf 1", distance 110, metric 200  Tag 1  , type extern 2, forward metric 1562   Last update from 10.1.1.2 on Serial0/1, 00:04:40 ago   Routing Descriptor Blocks:   * 10.1.1.2, from 2.2.2.2, 00:04:40 ago, via Serial0/1       Route metric is 200, traffic share count is 1 

Configuration Example: 5 Controlling Route Redistribution Based on Tag Values

In Figure 14-4, Router B is learning six routes via EIGRP. The EIGRP routes are redistributed into OSPF with the classful routes assigned a tag of 2 and the classless routes a tag of 1. Router A is redistributing the OSPF external routes into RIP-2. The policy is to redistribute only the classless routes into RIP-2. This can be accomplished using a route map and an IP access list. Because the external routes have been tagged, a route map can be used that redistributes only routes with a tag value equal to 1. Configure the routers as shown in the listing that follows the figure. Initially, all OSPF routes will be redistributed into RIP-2 on Router A.

Figure 14-4. A Route Map Can Be Used to Control Route Redistribution Based on the Tag Value

 Router A  interface Loopback0   ip address 1.1.1.1 255.255.255.255   !   interface Serial0/0   bandwidth 64   ip address 10.1.1.9 255.255.255.252   no ip mroute-cache   !   interface Serial0/1   bandwidth 64   ip address 10.1.1.1 255.255.255.252   clockrate 64000   !   router ospf 1   network 10.1.1.0 0.0.0.3 area 0   !   router rip   version 2   redistribute ospf 1 metric 1   passive-interface Serial0/1   network 10.0.0.0   no auto-summary  _______________________________________________________________________ Router B  interface Loopback0   ip address 2.2.2.2 255.255.255.255   !   interface Serial0   bandwidth 64   ip address 10.1.1.2 255.255.255.252   no ip directed-broadcast   !   interface Serial1   bandwidth 64   ip address 10.1.1.5 255.255.255.252   clockrate 64000   !   !   router eigrp 1   network 10.0.0.0   !   router ospf 1   redistribute eigrp 1 subnets route-map set-tags   network 10.1.1.0 0.0.0.3 area 0   !   access-list 1 permit 6.0.0.0 0.15.255.255   access-list 1 permit 146.6.0.0 0.0.15.255   access-list 1 permit 206.6.6.0 0.0.0.15   access-list 1 permit 10.1.1.4 0.0.0.3   route-map set-tags permit 10   match ip address 1   set tag 1   !   route-map set-tags permit 20   set tag 2  _______________________________________________________________________ Router C  interface Loopback0   ip address 3.3.3.3 255.255.255.255   !   interface Loopback1   ip address 5.5.5.5 255.0.0.0   !   interface Loopback2   ip address 6.6.6.6 255.240.0.0   !   interface Loopback3   ip address 145.5.5.5 255.255.0.0   !   interface Loopback4   ip address 146.6.6.6 255.255.240.0   !   interface Loopback5   ip address 205.5.5.5 255.255.255.0   !   interface Loopback6   ip address 206.6.6.6 255.255.255.240   !   interface Serial0   bandwidth 64   ip address 10.1.1.6 255.255.255.252   no ip directed-broadcast   !   router eigrp 1   network 5.0.0.0   network 6.0.0.0   network 10.0.0.0   network 145.5.0.0   network 146.6.0.0   network 205.5.5.0   network 206.6.6.0   no auto-summary  _______________________________________________________________________ Router D  interface Serial0/1   ip address 10.1.1.10 255.255.255.252   clockrate 64000   !   router rip   version 2   network 10.0.0.0  

Verify that Router D is receiving the redistributed OSPF routes from Router A.

 rtrD#  show ip route  Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP        D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area        N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2        E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP        i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, * - candidate default        U - per-user static route, o - ODR Gateway of last resort is not set  R    205.5.5.0/24 [120/1] via 10.1.1.9, 00:00:01, Serial0/1  206.6.6.0/28 is subnetted, 1 subnets  R       206.6.6.0 [120/1] via 10.1.1.9, 00:00:02, Serial0/1   R    5.0.0.0/8 [120/1] via 10.1.1.9, 00:00:02, Serial0/1  6.0.0.0/12 is subnetted, 1 subnets  R       6.0.0.0 [120/1] via 10.1.1.9, 00:00:02, Serial0/1  172.16.0.0/24 is subnetted, 1 subnets  R       172.16.1.0 [120/1] via 10.1.1.9, 00:00:02, Serial0/1   R    145.5.0.0/16 [120/1] via 10.1.1.9, 00:00:02, Serial0/1  10.0.0.0/30 is subnetted, 3 subnets C       10.1.1.8 is directly connected, Serial0/1  R       10.1.1.0 [120/1] via 10.1.1.9, 00:00:02, Serial0/1   R       10.1.1.4 [120/1] via 10.1.1.9, 00:00:02, Serial0/1  146.6.0.0/20 is subnetted, 1 subnets  R       146.6.0.0 [120/1] via 10.1.1.9, 00:00:05, Serial0/1  

Modify the configuration on Router A so that only OSPF routes with a tag value of 1 get redistributed into RIP.

 Router A  router rip   version 2    redistribute ospf 1 metric 1 route-map check-tags    passive-interface Serial0/1   network 10.0.0.0   no auto-summary   !    route-map check-tags permit 10      match tag 1   

Verification

Verify that the only OSPF routes redistributed into RIP on Router A are those routes with a tag value of 1.

 rtrD#  show ip route  Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP        D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area        N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2        E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP        i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, * - candidate default        U - per-user static route, o - ODR Gateway of last resort is not set      206.6.6.0/28 is subnetted, 1 subnets  R       206.6.6.0 [120/1] via 10.1.1.9, 00:00:01, Serial0/1  6.0.0.0/12 is subnetted, 1 subnets  R       6.0.0.0 [120/1] via 10.1.1.9, 00:00:02, Serial0/1  10.0.0.0/30 is subnetted, 3 subnets C       10.1.1.8 is directly connected, Serial0/1  R       10.1.1.0 [120/1] via 10.1.1.9, 00:00:02, Serial0/1   R       10.1.1.4 [120/1] via 10.1.1.9, 00:00:02, Serial0/1  146.6.0.0/20 is subnetted, 1 subnets  R       146.6.0.0 [120/1] via 10.1.1.9, 00:00:02, Serial0/1  

Troubleshooting

Step 1. Verify that the routes have been assigned the proper tags by using the command show ip ospf database external or the command show ip route ip-address mask.

Step 2. Verify that the redistribute command is referencing the correct routing process and process number (if applicable).

Step 3. Verify that the redistribute command is referencing the correct route map name.

Step 4. Verify the syntax and logic of the route map.

To avoid problems associated with mutual redistribution, use a distribute list (see Sections 7-5, 7-10, and 7-15) or a route map to allow only routes that have originated in the routing process domain. For example, if EIGRP is redistributed into OSPF and OSPF is redistributed into EIGRP on the same router, then OSPF routes will be redistributed back into OSPF from EIGRP and EIGRP routes will be redistributed back into EIGRP from OSPF. Using a route map or distribute list will prevent this from occurring.