10-4 redistribute protocol route-map route-map-name metric metric
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Syntax Description:
protocol— Routes learned via protocol will be redistributed into BGP.
route-map-name— Name of the route map used to control which routes will be redistributed into BGP. The route map can also be used to modify the BGP attributes of the redistributed routes.
metric— Metric to assign to the redistributed routes. The value is in the range of 0 to 4294967295.
Purpose: To redistribute routes into BGP that have been learned via a routing protocol other than BGP. The metric of the non-BGP-learned routes is transferred to the metric or multi-exit discriminator (MED) of the new BGP route if the metric option is not used. If the metric option is used, the assigned metric will be applied to all routes redistributed from the protocol. A route map can be used for each redistributed protocol to control which routes are redistributed. A route map can also be used to modify the BGP attributes of the redistributed routes. Routes can be redistributed from connected, dvmrp, egp, eigrp, igrp, isis, iso-igrp, mobile, odr, ospf, rip, and static.
Cisco IOS Software Release: 10.0
Configuration Example: Selectively Redistributing Connected, Static, and EIGRP Learned Routes into BGP
In Figure 10-3 , Router C is advertising 172.16.2.0/24 and 172.16.3.0/24 to Router B via EIGRP. Routers A and B have an EBGP relationship. This example redistributes EIGRP
Router A
interface loopback 0
ip address 172.16.0.1 255.255.255.0
!
interface loopback 1
ip address 172.16.1.1 255.255.255.0
!
router bgp 1
network 172.17.1.0 mask 255.255.255.0
neighbor 172.17.1.1 remote-as 2
___________________________________________________________________________
Router B
router eigrp 1
network 10.0.0.0
network 172.17.0.0
no auto-summary
!
router bgp 2
network 10.1.0.0 mask 255.255.255.252
network 172.17.1.0 mask 255.255.255.0
neighbor 172.17.1.2 remote-as 1
!
ip route 172.16.4.0 255.255.255.0 s2/0
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Router C
interface loopback 0
ip address 172.16.2.1 255.255.255.0
!
interface loopback 1
ip address 172.16.3.1 255.255.255.0
!
router eigrp 1
network 172.16.0.0
network 10.0.0.0
no auto-summary
Before proceeding with the redistribution and filtering of routes into BGP, inspect the IP and BGP routing tables on Routers A and B. Router B should be learning routes 172.16.2.0/24 and 172.16.3.0/24 from Router C via EIGRP. Because you are not redistributing routes on Router B, Router A should not be learning about the 172.16.2.0/24 or 172.16.3.0/24
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, 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
172.17.0.0/24 is subnetted, 1 subnets
C 172.17.1.0 is directly connected, Ethernet0/0
172.16.0.0/24 is subnetted, 3 subnets
S 172.16.4.0 is directly connected, Serial2/0
D 172.16.2.0 [90/1889792] via 10.1.1.2, 00:26:32, Serial2/0
D 172.16.3.0 [90/1889792] via 10.1.1.2, 00:26:32, Serial2/0
10.0.0.0/30 is subnetted, 1 subnets
C 10.1.1.0 is directly connected, Serial2/0
rtrB#show ip bgp
BGP table version is 3, local router ID is 172.17.1.1
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
*> 10.1.1.0/30 0.0.0.0 0 32768 i
* 172.17.1.0/24 172.17.1.2 0 0 1 i
*> 0.0.0.0 0 32768 i
___________________________________________________________________________
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
172.17.0.0/24 is subnetted, 1 subnets
C 172.17.1.0 is directly connected, FastEthernet0
172.16.0.0/24 is subnetted, 2 subnets
C 172.16.0.0 is directly connected, Loopback0
C 172.16.1.0 is directly connected, Loopback1
10.0.0.0/30 is subnetted, 1 subnets
B 10.1.1.0 [20/0] via 172.17.1.1, 00:25:38
rtrA#show ip bgp
BGP table version is 4, local router ID is 172.16.1.1
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
*> 10.1.1.0/30 172.17.1.1 0 0 2 i
*> 172.17.1.0/24 0.0.0.0 0 32768 i
* 172.17.1.1 0 0 2 i
Notice that the metric for the EIGRP learned routes on Router B is 1889792. Because the form of the redistribute command that you will use does not contain a metric, the router will use the EIGRP metric for the BGP MED for the redistributed EIGRP routes. Now modify the BGP configuration on Router B to enable the redistribution of the EIGRP and static routes into BGP. Also modify the configuration on Router A to enable the redistribution of connected routes. On Router A, allow only the connected network
Router A
router bgp 1
network 172.17.1.0 mask 255.255.255.0
redistribute connected route-map allow
neighbor 172.17.1.1 remote-as 2
no auto-summary
!
access-list 1 permit 172.16.1.0 0.0.0.255
route-map allow permit 10
match ip address 1
___________________________________________________________________________
Router B
router bgp 1
network 10.1.0.0 mask 255.255.255.0
network 172.17.1.0 mask 255.255.255.0
redistribute static route-map setwt
redistribute eigrp 1 route-map block
neighbor 172.17.1.2 remote-as 2
no auto-summary
!
access-list 1 deny 172.16.2.0 0.0.0.255
access-list 1 permit any
route-map block permit 10
match ip add 1
route-map setwt permit 10
set weight 88
Verification
Verify that the selected connected routes are being redistributed in BGP on Router A and
rtrA#show ip bgp
BGP table version is 14, local router ID is 172.16.1.1
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
*> 10.1.1.0/30 172.17.1.1 0 0 2 i
*> 172.16.1.0/24 0.0.0.0 0 32768 ?
*> 172.16.3.0/24 172.17.1.1 1889792 0 2 ?
*> 172.16.4.0/24 172.17.1.1 0 0 2 ?
* 172.17.1.0/24 172.17.1.1 0 0 2 i
*> 0.0.0.0 0 32768 I
___________________________________________________________________________
rtrB#show ip bgp
BGP table version is 6, local router ID is 172.17.1.1
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
*> 10.1.1.0/30 0.0.0.0 0 32768 i
*> 172.16.1.0/24 172.17.1.2 0 0 1 ?
*> 172.16.3.0/24 10.1.1.2 1889792 32768 ?
*> 172.16.4.0/24 0.0.0.0 0 88 ?
* 172.17.1.0/24 172.17.1.2 0 0 1 i
*> 0.0.0.0 0 32768 i
Troubleshooting
Step 1. Verify that the BGP neighbors are in the Established state using the show ip bgp neighbors command.
If the neighbor relationship is not in the Established state, see section 8-23 .
Step 2. Verify that the protocol you are redistributing routes from is active on the router.Step 3. When redistributing from a protocol that requires a process ID, verify that you are using the proper process ID in the redistribute command.Step 4. Use the no auto-summary command under router BGP when redistributing routes into BGP.Step 5. Verify the syntax of any route maps and access lists. Remember that an IP
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