General syntax:
redistribute protocol [process-id | as-number] [metric bw delay reliability load mtu ] [match {internal | nssa-external | external 1 | external 2}] [tag tagvalue] [route-map name]
Parameters:
-protocol: The source of routing information. Includes RIP, OSPF, EIGRP, IS-IS, BGP, connected, and static.
-process-id/as-number: If redistributing a routing protocol that uses a process ID or ASN on the router global config command, use this parameter to refer to that process or ASN value.
-metric: A keyword after which follows the four metric components (bandwidth, delay, reliability, link load), plus the MTU associated with the route.
-match: If redistributing from OSPF, this keyword lets you match internal OSPF routes, external (by type), and NSSA external routes, essentially filtering which routes are redistributed.
-tag: Assigns a unitless integer value to the routes redistributed by this command - tags which can be later matched by other routers using a route-map.
-route-map: Apply the logic in the referenced route-map to filter routes, set metrics, and set route tags.
When redistributing another protocol into EIGRP, if we use only "redistribute protocol [process-id | as-number]" then the redistribution does not take place, even if the command is accepted by IOS.
EIGRP does not have a default setting for the metric components to use when redistributing into EIGRP from OSPF or any other routing protocol.
Consider router R4, which is sitting between an EIGRP and an OSPF domain. Both protocols have been configured, but no redistribution yet:
R4#show run
...
!
router eigrp 1
network 172.16.0.2 0.0.0.0
network 172.16.0.12 0.0.0.3
network 192.168.44.0
no auto-summary
!
router ospf 1
router-id 4.4.4.4
log-adjacency-changes
network 192.168.0.12 0.0.0.3 area 0
!
R4#show run | i redistribute
R4#
The EIGRP topology table on R4 shows only the routes learned from EIGRP. No OSPF routes reside in this table. Also, we can verify R6's routing table, showing nothing but routes to networks in the EIGRP domain:
R4#show ip eigrp topology
IP-EIGRP Topology Table for AS(1)/ID(192.168.44.44)
Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply,
r - reply Status, s - sia Status
P 192.168.44.0/24, 1 successors, FD is 128256
via Connected, Loopback44
P 192.168.55.0/24, 1 successors, FD is 2297856
via 172.16.0.14 (2297856/128256), Serial0/2
via 172.16.0.1 (2323456/409600), Serial0/0
P 172.16.0.12/30, 1 successors, FD is 2169856
via Connected, Serial0/2
P 172.16.0.8/30, 1 successors, FD is 2681856
via 172.16.0.1 (2681856/2169856), Serial0/0
via 172.16.0.14 (2707456/2195456), Serial0/2
P 172.16.0.4/30, 2 successors, FD is 2195456
via 172.16.0.1 (2195456/281600), Serial0/0
via 172.16.0.14 (2195456/281600), Serial0/2
P 172.16.0.0/30, 1 successors, FD is 2169856
via Connected, Serial0/0
P 172.16.111.0/24, 1 successors, FD is 2297856
via 172.16.0.1 (2297856/128256), Serial0/0
via 172.16.0.14 (2323456/409600), Serial0/2
R6#show ip route
Codes: C - connected, S - static, 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
i - IS-IS, su - IS-IS summary, 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
D 192.168.44.0/24 [90/2297856] via 172.16.0.2, 00:31:28, Serial0/0
172.16.0.0/16 is variably subnetted, 5 subnets, 2 masks
D 172.16.0.12/30 [90/2195456] via 172.16.0.6, 00:31:28, FastEthernet0/1
C 172.16.0.8/30 is directly connected, Serial0/1
C 172.16.0.4/30 is directly connected, FastEthernet0/1
C 172.16.0.0/30 is directly connected, Serial0/0
C 172.16.111.0/24 is directly connected, Loopback111
D 192.168.55.0/24 [90/409600] via 172.16.0.6, 00:31:28, FastEthernet0/1
Now, let's configure redistribution into EIGRP with no other parameters other than the protocol and process-id:
R4(config)#router eigrp 1
R4(config-router)#redistribute ospf 1
Let's verify the topology table on R4 and the routing table on R6 again:
R4#show ip eigrp topology
IP-EIGRP Topology Table for AS(1)/ID(192.168.44.44)
Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply,
r - reply Status, s - sia Status
P 192.168.44.0/24, 1 successors, FD is 128256
via Connected, Loopback44
P 192.168.55.0/24, 1 successors, FD is 2297856
via 172.16.0.14 (2297856/128256), Serial0/2
via 172.16.0.1 (2323456/409600), Serial0/0
P 172.16.0.12/30, 1 successors, FD is 2169856
via Connected, Serial0/2
P 172.16.0.8/30, 1 successors, FD is 2681856
via 172.16.0.1 (2681856/2169856), Serial0/0
via 172.16.0.14 (2707456/2195456), Serial0/2
P 172.16.0.4/30, 2 successors, FD is 2195456
via 172.16.0.1 (2195456/281600), Serial0/0
via 172.16.0.14 (2195456/281600), Serial0/2
P 172.16.0.0/30, 1 successors, FD is 2169856
via Connected, Serial0/0
P 172.16.111.0/24, 1 successors, FD is 2297856
via 172.16.0.1 (2297856/128256), Serial0/0
via 172.16.0.14 (2323456/409600), Serial0/2
R6#show ip route
Codes: C - connected, S - static, 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
i - IS-IS, su - IS-IS summary, 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
D 192.168.44.0/24 [90/2297856] via 172.16.0.2, 00:34:04, Serial0/0
172.16.0.0/16 is variably subnetted, 5 subnets, 2 masks
D 172.16.0.12/30 [90/2195456] via 172.16.0.6, 00:34:04, FastEthernet0/1
C 172.16.0.8/30 is directly connected, Serial0/1
C 172.16.0.4/30 is directly connected, FastEthernet0/1
C 172.16.0.0/30 is directly connected, Serial0/0
C 172.16.111.0/24 is directly connected, Loopback111
D 192.168.55.0/24 [90/409600] via 172.16.0.6, 00:34:04, FastEthernet0/1
As we can see, both tables are unchanged, since no routes have been redistributed from OSPF.
Now, there are 3 methods to make this work for EIGRP:
-Setting the default for all redistribute commands with the "default-metric" command.
-Setting the component metrics applied to all routes redistributed by a single "redistribute" command, using the "metric" parameters.
-Setting different component metrics to different routes from a single route source, using the "route-map" parameter inside the "redistribute" command.
Note: When redistributing into EIGRP from another protocol, the default metric is infinite (same for RIP). EIGRP does have a default metric when redistributing from another EIGRP process, in which case it takes the metric from the source of the routing information.
Now, returning to R4, let's use the first method:
R4(config)#router eigrp 1
R4(config-router)#default-metric ?
<1-4294967295> Bandwidth in Kbits per second
R4(config-router)#default-metric 1544 ?
<0-4294967295> Delay metric, in 10 microsecond units
R4(config-router)#default-metric 1544 2000 ?
<0-255> Reliability metric where 255 is 100% reliable
R4(config-router)#default-metric 1544 2000 255 ?
<1-255> Effective bandwidth metric (Loading) where 255 is 100% loaded
R4(config-router)#default-metric 1544 2000 255 1 ?
<1-65535> Maximum Transmission Unit metric of the path
R4(config-router)#default-metric 1544 2000 255 1 1500
Verifying again the topology table on R4 and the routing table on R6:
R4#show ip eigrp topology
IP-EIGRP Topology Table for AS(1)/ID(192.168.44.44)
Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply,
r - reply Status, s - sia Status
P 10.0.1.3/32, 1 successors, FD is 2169856
via Redistributed (2169856/0)
P 10.0.1.2/32, 1 successors, FD is 2169856
via Redistributed (2169856/0)
P 10.0.1.1/32, 1 successors, FD is 2169856
via Redistributed (2169856/0)
P 10.0.10.10/32, 1 successors, FD is 2169856
via Redistributed (2169856/0)
P 10.0.11.11/32, 1 successors, FD is 2169856
via Redistributed (2169856/0)
P 192.168.44.0/24, 1 successors, FD is 128256
via Connected, Loopback44
P 192.168.55.0/24, 1 successors, FD is 2297856
via 172.16.0.14 (2297856/128256), Serial0/2
via 172.16.0.1 (2323456/409600), Serial0/0
P 192.168.0.12/30, 1 successors, FD is 2169856
via Redistributed (2169856/0)
P 192.168.33.33/32, 1 successors, FD is 2169856
via Redistributed (2169856/0)
P 192.168.100.100/32, 1 successors, FD is 2169856
via Redistributed (2169856/0)
P 192.168.0.0/29, 1 successors, FD is 2169856
via Redistributed (2169856/0)
P 192.168.13.13/32, 1 successors, FD is 2169856
via Redistributed (2169856/0)
P 192.168.3.0/30, 1 successors, FD is 2169856
via Redistributed (2169856/0)
P 192.168.169.170/32, 1 successors, FD is 2169856
via Redistributed (2169856/0)
P 192.168.0.16/30, 1 successors, FD is 2169856
via Redistributed (2169856/0)
P 192.168.0.20/30, 1 successors, FD is 2169856
via Redistributed (2169856/0)
P 172.16.0.12/30, 1 successors, FD is 2169856
via Connected, Serial0/2
P 172.16.0.8/30, 1 successors, FD is 2681856
via 172.16.0.1 (2681856/2169856), Serial0/0
via 172.16.0.14 (2707456/2195456), Serial0/2
P 172.16.0.4/30, 2 successors, FD is 2195456
via 172.16.0.1 (2195456/281600), Serial0/0
via 172.16.0.14 (2195456/281600), Serial0/2
P 172.16.0.0/30, 1 successors, FD is 2169856
via Connected, Serial0/0
P 192.168.168.0/30, 1 successors, FD is 2169856
via Redistributed (2169856/0)
P 172.16.111.0/24, 1 successors, FD is 2297856
via 172.16.0.1 (2297856/128256), Serial0/0
via 172.16.0.14 (2323456/409600), Serial0/2
R6#show ip route
Codes: C - connected, S - static, 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
i - IS-IS, su - IS-IS summary, 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
192.168.13.0/32 is subnetted, 1 subnets
D EX 192.168.13.13 [170/2681856] via 172.16.0.2, 00:02:29, Serial0/0
D 192.168.44.0/24 [90/2297856] via 172.16.0.2, 00:45:18, Serial0/0
172.16.0.0/16 is variably subnetted, 5 subnets, 2 masks
D 172.16.0.12/30 [90/2195456] via 172.16.0.6, 00:45:18, FastEthernet0/1
C 172.16.0.8/30 is directly connected, Serial0/1
C 172.16.0.4/30 is directly connected, FastEthernet0/1
C 172.16.0.0/30 is directly connected, Serial0/0
C 172.16.111.0/24 is directly connected, Loopback111
D 192.168.55.0/24 [90/409600] via 172.16.0.6, 00:45:20, FastEthernet0/1
10.0.0.0/32 is subnetted, 5 subnets
D EX 10.0.1.3 [170/2681856] via 172.16.0.2, 00:02:30, Serial0/0
D EX 10.0.1.2 [170/2681856] via 172.16.0.2, 00:02:30, Serial0/0
D EX 10.0.11.11 [170/2681856] via 172.16.0.2, 00:02:32, Serial0/0
D EX 10.0.10.10 [170/2681856] via 172.16.0.2, 00:02:32, Serial0/0
D EX 10.0.1.1 [170/2681856] via 172.16.0.2, 00:02:32, Serial0/0
192.168.0.0/24 is variably subnetted, 4 subnets, 2 masks
D EX 192.168.0.12/30 [170/2681856] via 172.16.0.2, 00:02:32, Serial0/0
D EX 192.168.0.0/29 [170/2681856] via 172.16.0.2, 00:02:32, Serial0/0
D EX 192.168.0.16/30 [170/2681856] via 172.16.0.2, 00:02:32, Serial0/0
D EX 192.168.0.20/30 [170/2681856] via 172.16.0.2, 00:02:32, Serial0/0
192.168.168.0/30 is subnetted, 1 subnets
D EX 192.168.168.0 [170/2681856] via 172.16.0.2, 00:02:32, Serial0/0
192.168.100.0/32 is subnetted, 1 subnets
D EX 192.168.100.100 [170/2681856] via 172.16.0.2, 00:02:32, Serial0/0
192.168.169.0/32 is subnetted, 1 subnets
D EX 192.168.169.170 [170/2681856] via 172.16.0.2, 00:02:32, Serial0/0
192.168.3.0/30 is subnetted, 1 subnets
D EX 192.168.3.0 [170/2681856] via 172.16.0.2, 00:02:33, Serial0/0
192.168.33.0/32 is subnetted, 1 subnets
D EX 192.168.33.33 [170/2681856] via 172.16.0.2, 00:02:33, Serial0/0
Notes/Conclusions:
-The "D EX" routes are the routes R4 redistributed from the OSPF domain. They are marked as external, having the default AD of external EIGRP routes, 170.
-In R4's topology table, we notice that all redistributed routes are marked with "via Redistributed", having the same Feasible Distance (FD), because all use the same component metrics per the configured "default-metric" command.
-R4's connected subnet (192.168.0.12/30) was also redistributed, even though this route is a connected route for R4 and not an OSPF route.
-The default metrics we configured and the protocol from which the routes came are confirmed for each route in the EIGRP topology table:
R4#show ip eigrp topology 192.168.0.0/29
IP-EIGRP (AS 1): Topology entry for 192.168.0.0/29
State is Passive, Query origin flag is 1, 1 Successor(s), FD is 2169856
Routing Descriptor Blocks:
192.168.0.13, from Redistributed, Send flag is 0x0
Composite metric is (2169856/0), Route is External
Vector metric:
Minimum bandwidth is 1544 Kbit
Total delay is 20000 microseconds
Reliability is 255/255
Load is 1/255
Minimum MTU is 1500
Hop count is 0
External data:
Originating router is 192.168.44.44 (this system)
AS number of route is 1
External protocol is OSPF, external metric is 74
Administrator tag is 0 (0x00000000)
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