How Redistribution works?
·
Each
protocol has different metric to find the best path, so we must be careful
while redistributing routes from one protocol to another protocol.
·
But,
if we see how redistribution works, there are 2 basic steps the router goes
through for redistributing routes from one protocol to another protocol.
·
Example: Let’s assume Router A wants to redistribute routes
from EIGRP to OSPF
·
Step 1: Router
first finds the EIGRP routes; “show ip route eigrp” will show the routes which
router is using EIGRP to reach them and redistributes them into OSPF.
·
Step 2: Router
then finds the connected interfaces that are part of EIGRP and redistributing
them into OSPF.
·
Let
me take a small topology to configure this one:
EIGRP--------------------------EIGRP----OSPF-------------------------OSPF
R2----s1/0-----------------s1/0------R1-----s1/1--------------s1/1----R3
10.1.12.2-------------------10.1.12.2---10.1.13.1---------------10.1.13.3
Configs before
redistribution:
R2(config-router)#do show run | sec router
router
eigrp 100
network 2.2.2.2 0.0.0.0
network 10.1.12.2 0.0.0.0
no auto-summary
auto-summary
eigrp router-id 2.2.2.2
R2(config-router)#
R1(config-router)#do show run | sec router
router
eigrp 100
network 10.1.12.1 0.0.0.0
no auto-summary
auto-summary
eigrp router-id 1.1.1.1
router
ospf 1
router-id 1.1.1.1
log-adjacency-changes
network 10.1.13.1 0.0.0.0 area 0
R1(config-router)#
R3(config-router)#do show run | sec router
router
ospf 1
router-id 3.3.3.3
log-adjacency-changes
network 3.3.3.3 0.0.0.0 area 0
network 10.1.13.3 0.0.0.0 area 0
R3(config-router)#
R3(config-router)#
·
Now, let’s see the
routing tables:
R2(config-if)#do 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
2.0.0.0/32 is subnetted, 1 subnets
C 2.2.2.2 is directly connected, Loopback0
10.0.0.0/24 is subnetted, 1 subnets
C 10.1.12.0 is directly connected,
Serial1/0
R2(config-if)#
Observation:
·
10.1.12.0
is part of EIGRP
·
2.2.2.2
is part of EIGRP
·
But,
these interfaces are connected, that’s why they are not showing up as EIGRP
routes.
·
R2
is not learning about R3’s loopback 3.3.3.3, because of no redistribution in R1
from OSPF to EIGRP
R3#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
3.0.0.0/32 is subnetted, 1 subnets
C 3.3.3.3 is directly connected, Loopback0
10.0.0.0/24 is subnetted, 1 subnets
C 10.1.13.0 is directly connected,
Serial1/1
R3#
Observation:
·
10.1.13.0
is part of OSPF
·
3.3.3.3
is part of OSPF
·
But,
these interfaces are connected, that’s why they are not showing up as OSPF
routes.
·
R3
is not learning about R2’s loopback 2.2.2.2, because of no redistribution in R1
from IEGRP to OSPF
R1(config-if)#do 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
2.0.0.0/32 is subnetted, 1 subnets
D
2.2.2.2 [90/2297856] via 10.1.12.2, 00:03:02, Serial1/0
3.0.0.0/32 is subnetted, 1 subnets
O
3.3.3.3 [110/65] via 10.1.13.3, 00:34:05, Serial1/1
10.0.0.0/24 is subnetted, 2 subnets
C 10.1.13.0 is directly connected,
Serial1/1
C 10.1.12.0 is directly connected,
Serial1/0
R1(config-if)#
Observation:
·
10.1.12.0
is part of EIGRP, but it’s connected interface
·
2.2.2.2
is learning via EIGRP,
·
10.1.13.0
is part of OSPF, but it’s connected interface
·
3.3.3.3
is learning via OSPF
·
Let
me configure redistribution between OSPF and EIGRP in R1 so that R2 and R3
learn other router’s loopbacks.
R1(config-if)#router
ospf 1
R1(config-router)#redistribute eigrp 100 subnets
R1(config-router)#exit
R1(config)#router
eigrp 100
R1(config-router)#redistribute ospf 1 metric 1 1 1 1 1
R1(config-router)#
R2#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
2.0.0.0/32 is subnetted, 1 subnets
C 2.2.2.2 is directly connected, Loopback0
3.0.0.0/32 is subnetted, 1 subnets
D EX
3.3.3.3 [170/2560512256] via 10.1.12.1, 00:02:07, Serial1/0
10.0.0.0/24 is subnetted, 2 subnets
D EX
10.1.13.0 [170/2560512256] via 10.1.12.1, 00:02:07, Serial1/0
C 10.1.12.0 is directly connected,
Serial1/0
R2#
R3#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
2.0.0.0/32 is subnetted, 1 subnets
O E2
2.2.2.2 [110/20] via 10.1.13.1, 00:02:41, Serial1/1
3.0.0.0/32 is subnetted, 1 subnets
C 3.3.3.3 is directly connected, Loopback0
10.0.0.0/24 is subnetted, 2 subnets
C 10.1.13.0 is directly connected,
Serial1/1
O E2
10.1.12.0 [110/20] via 10.1.13.1, 00:02:41, Serial1/1
R3#
R1#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
2.0.0.0/32 is subnetted, 1 subnets
D 2.2.2.2 [90/2297856] via 10.1.12.2,
00:16:48, Serial1/0
3.0.0.0/32 is subnetted, 1 subnets
O 3.3.3.3 [110/65] via 10.1.13.3,
00:02:57, Serial1/1
10.0.0.0/24 is subnetted, 2 subnets
C 10.1.13.0 is directly connected,
Serial1/1
C 10.1.12.0 is directly connected,
Serial1/0
R1#
Observation:
·
R2
is learning R3’s loopback 3.3.3.3 and
·
R2
is also learning R1-R3 link 10.1.13.0, this is happening because of Step-2 in
the redistribution process.
·
R3
is learning R2’s loopback 2.2.2.2 and
·
R3
is also learning R1-R2 link 10.1.12.0, this is happening because of Step-2 in
the redistribution process.
·
During
redistribution, step-2 happens by default
·
If
we do something else which overwrites default behavior, then we are in trouble.
·
For step-2, router creates default route-map and if we create our
own route-map to redistribute and if we forget add permit statement at the end,
then we are in trouble.
·
Let
me create a loopback interface in R1 and create a route-map to redistribute
this loopback into OSPF
R1(config)#int
loop0
R1(config-if)#ip
address 1.1.1.1 255.255.255.255
R1(config-if)#route-map
CONN
R1(config-route-map)#match
interface loopback 0
R1(config-route-map)#router
ospf 1
R1(config-router)#redistribute connected subnets route-map CONN
R1(config-router)#
·
Now,
let me check the R3’s routing table:
R3#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
1.0.0.0/32 is subnetted, 1 subnets
O E2
1.1.1.1 [110/20] via 10.1.13.1, 00:00:27, Serial1/1
2.0.0.0/32 is subnetted, 1 subnets
O E2
2.2.2.2 [110/20] via 10.1.13.1, 00:15:08, Serial1/1
3.0.0.0/32 is subnetted, 1 subnets
C 3.3.3.3 is directly connected, Loopback0
10.0.0.0/24 is subnetted, 1 subnets
C 10.1.13.0 is directly connected,
Serial1/1
R3#
Observation:
·
R3
has R1’s loopback 1.1.1.1
·
But
what happened to R1-R2 link 10.1.12.0 we had earlier?
·
But
the route-map I created doesn’t have permit statement at the end.
·
Now,
let me add permit statement at the end for the route-map
R1(config-router)#route-map CONN permit 20
·
Now, let me check R3’s routing table:
R3#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
1.0.0.0/32 is subnetted, 1 subnets
O E2
1.1.1.1 [110/20] via 10.1.13.1, 00:04:32, Serial1/1
2.0.0.0/32 is subnetted, 1 subnets
O E2
2.2.2.2 [110/20] via 10.1.13.1, 00:19:13, Serial1/1
3.0.0.0/32 is subnetted, 1 subnets
C 3.3.3.3 is directly connected, Loopback0
10.0.0.0/24 is subnetted, 2 subnets
C 10.1.13.0 is directly connected,
Serial1/1
O E2
10.1.12.0 [110/20] via 10.1.13.1, 00:00:27, Serial1/1
R3#
Observation:
·
R3
has R1-R2 link 10.1.12.0
·
This
is because I have added permit statement at the end of the route-map now.
·
We
have to take of the redistribution process, especially if we redistribute any
connected interfaces using route-map
·
However if we are redistributing from IS-IS, IS-IS will not do the 2nd
step and hence we need to manually redistribute the connected interface link by
using “redistribute connected” command.
·
In IPV6, all the protocols follow only step-1 and they don’t follow
the step-2 and hence we need to explicitly mention “include-connected” key-word
at the end of the redistribution.
Case-1: Let me configure IS-IS between R1-R2 instead of EIGRP
and see:
IS-IS--------------------------IS-IS----OSPF-------------------------OSPF
R2----s1/0-----------------s1/0------R1-----s1/1--------------s1/1----R3
10.1.12.2-------------------10.1.12.2---10.1.13.1---------------10.1.13.3
Configs:
R1(config)#router
isis 1
R1(config-router)#net
49.0001.1111.1111.1111.00
R1(config-router)#int
ser1/0
R1(config-if)#ip
router isis 1
R1(config-if)#router
isis 1
R1(config-router)#is-type
level-2-only
R1(config-router)#
R2(config)#router
isis 1
R2(config-router)#net
49.0001.2222.2222.2222.00
R2(config-router)#int
ser1/0
R2(config-if)#ip
router isis 1
R2(config-if)#int
loop0
R2(config-if)#ip
router isis 1
R2(config-if)#router
isis 1
R2(config-router)#is-type
level-2-only
R2(config-router)#
R1(config-router)#do
show run | sec router
ip router isis 1
router
ospf 1
router-id 1.1.1.1
log-adjacency-changes
redistribute connected
network 10.1.13.1 0.0.0.0 area 0
router
isis 1
net 49.0001.1111.1111.1111.00
is-type level-2-only
R1(config-router)#
R3#show
run | sec router
router
ospf 1
router-id 3.3.3.3
log-adjacency-changes
network 3.3.3.3 0.0.0.0 area 0
network 10.1.13.3 0.0.0.0 area 0
R3#
R2(config-router)#do
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
2.0.0.0/32 is subnetted, 1 subnets
C 2.2.2.2 is directly connected, Loopback0
10.0.0.0/24 is subnetted, 1 subnets
C 10.1.12.0 is directly connected,
Serial1/0
R2(config-router)#
R1(config-router)#do
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
1.0.0.0/32 is subnetted, 1 subnets
C 1.1.1.1 is directly connected, Loopback0
2.0.0.0/32 is subnetted, 1 subnets
i L2
2.2.2.2 [115/20] via 10.1.12.2, Serial1/0
3.0.0.0/32 is subnetted, 1 subnets
O
3.3.3.3 [110/65] via 10.1.13.3, 00:14:12, Serial1/1
10.0.0.0/24 is subnetted, 2 subnets
C 10.1.13.0 is directly connected,
Serial1/1
C 10.1.12.0 is directly connected,
Serial1/0
R1(config-router)#
R3#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
3.0.0.0/32 is subnetted, 1 subnets
C 3.3.3.3 is directly connected, Loopback0
10.0.0.0/24 is subnetted, 1 subnets
C 10.1.13.0 is directly connected,
Serial1/1
R3#
Observation:
·
R1
is learning about R2’s loopback 2.2.2.2 from IS-IS
·
R1
is learning about R3’s loopback 3.3.3.3 from OSPF
·
Now, let me redistribute between IS-IS and OSPF in R2
R1(config-router)#router isis 1
R1(config-router)#redistribute
ospf 1 metric 10
R1(config-router)#router ospf 1
R1(config-router)#redistribute
isis 1 subnets
R1(config-router)#
·
Now,
let me see the Routing tables:
R2(config-router)#do
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
2.0.0.0/32 is subnetted, 1 subnets
C 2.2.2.2 is directly connected, Loopback0
3.0.0.0/32 is subnetted, 1 subnets
i L2
3.3.3.3 [115/20] via 10.1.12.1, Serial1/0
10.0.0.0/24 is subnetted, 2 subnets
i L2
10.1.13.0 [115/20] via 10.1.12.1, Serial1/0
C 10.1.12.0 is directly connected,
Serial1/0
R2(config-router)#
R1(config-router)#do
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
1.0.0.0/32 is subnetted, 1 subnets
C 1.1.1.1 is directly connected, Loopback0
2.0.0.0/32 is subnetted, 1 subnets
i
L2 2.2.2.2 [115/20] via 10.1.12.2,
Serial1/0
3.0.0.0/32 is subnetted, 1 subnets
O 3.3.3.3 [110/65] via 10.1.13.3, 00:06:13,
Serial1/1
10.0.0.0/24 is subnetted, 2 subnets
C 10.1.13.0 is directly connected,
Serial1/1
C 10.1.12.0 is directly connected,
Serial1/0
R1(config-router)#
R3#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
2.0.0.0/32 is subnetted, 1 subnets
O E2
2.2.2.2 [110/20] via 10.1.13.1, 00:01:47, Serial1/1
3.0.0.0/32 is subnetted, 1 subnets
C 3.3.3.3 is directly connected, Loopback0
10.0.0.0/24 is subnetted, 1 subnets
C 10.1.13.0 is directly connected,
Serial1/1
R3#
Observations:
·
R2
has R3’s loopback 3.3.3.3 as well as R1-R3 link 10.1.13.0
·
That
is because when OSPF is redistributes into IS-IS, OSPF went through 2 steps
mentioned in the beginning and thus R2 has even the R1-R3 link.
·
But,
R3 has only R2’s loopback 2.2.2.2
·
R3
doesn’t have R1-R2 link
·
This
is because, when IS-IS is redistributed into OSPF, only IS-IS routes got
redistributed by default, it didn’t redistribute the connected interfaces that
are part of IS-IS
·
Solution
is to redistribute the connected interface explicitly under the OSPF process,
using the “redistribute connected” command
R1(config)#router
ospf 1
R1(config-router)#redistribute connected subnets
R1(config-router)#
R3#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
2.0.0.0/32 is subnetted, 1 subnets
O E2
2.2.2.2 [110/20] via 10.1.13.1, 00:14:01, Serial1/1
3.0.0.0/32 is subnetted, 1 subnets
C 3.3.3.3 is directly connected, Loopback0
10.0.0.0/24 is subnetted, 2 subnets
C 10.1.13.0 is directly connected,
Serial1/1
O E2
10.1.12.0 [110/20] via 10.1.13.1, 00:02:39, Serial1/1
R3#
Case-2: Let me configure IPv6 IEGRP and IPV6 OSPF now and see:
RIP------------------------------RIP----OSPF-------------------------OSPF
R2----s1/0-----------------s1/0------R1-----s1/1--------------s1/1----R3
2001:12::1-----------------
2001:12::1--- 2001:13::1------------
2001:13::3
Configs before
redistribution:
R2#show run |
sec router
ipv6
router rip RIPng
R2#
R2#show run
int ser1/0
Building
configuration...
Current
configuration : 151 bytes
!
interface
Serial1/0
ip address 10.1.12.2 255.255.255.0
ipv6 address 2001:12::2/64
ipv6 enable
ipv6 rip RIPng enable
serial restart-delay 0
end
R2#show run
int loop0
Building
configuration...
Current
configuration : 126 bytes
!
interface
Loopback0
ip address 2.2.2.2 255.255.255.255
ipv6 address 2001:2::2/64
ipv6 enable
ipv6 rip RIPng enable
end
R2#
R3#show run |
sec router
ipv6
router ospf 1
log-adjacency-changes
R3#
R3#show run
int ser1/1
Building
configuration...
Current
configuration : 164 bytes
!
interface
Serial1/1
ip address 10.1.13.3 255.255.255.0
ip flow egress
ipv6 address 2001:13::3/64
ipv6 enable
ipv6 ospf 1 area 0
serial restart-delay 0
end
R3#show run
int loop0
Building
configuration...
Current
configuration : 123 bytes
!
interface
Loopback0
ip address 3.3.3.3 255.255.255.255
ipv6 address 2001:3::3/64
ipv6 enable
ipv6 ospf 1 area 0
end
R3#
R1#show run
int ser1/0
Building
configuration...
Current
configuration : 168 bytes
!
interface
Serial1/0
ip address 10.1.12.1 255.255.255.0
ip flow ingress
ipv6 address 2001:12::1/64
ipv6 enable
ipv6 rip RIPng enable
serial restart-delay 0
end
R1#
R1#show run
int ser1/1
Building
configuration...
Current
configuration : 165 bytes
!
interface
Serial1/1
ip address 10.1.13.1 255.255.255.0
ip flow ingress
ipv6 address 2001:13::1/64
ipv6 enable
ipv6 ospf 1 area 0
serial restart-delay 0
end
R1#
·
Now, let’s see the routing tables:
R2#show ipv6
route
IPv6
Routing Table - 6 entries
Codes:
C - Connected, L - Local, S - Static, R - RIP, B - BGP
U - Per-user Static route
I1 - ISIS L1, I2 - ISIS L2, IA - ISIS
interarea, IS - ISIS summary
O - OSPF intra, OI - OSPF inter, OE1 -
OSPF ext 1, OE2 - OSPF ext 2
ON1 - OSPF NSSA ext 1, ON2 - OSPF NSSA
ext 2
C 2001:2::/64 [0/0]
via ::, Loopback0
L 2001:2::2/128 [0/0]
via ::, Loopback0
C 2001:12::/64 [0/0]
via ::, Serial1/0
L 2001:12::2/128 [0/0]
via ::, Serial1/0
L FE80::/10 [0/0]
via ::, Null0
L FF00::/8 [0/0]
via ::, Null0
R2#
R3#show ipv6
route
IPv6
Routing Table - 6 entries
Codes:
C - Connected, L - Local, S - Static, R - RIP, B - BGP
U - Per-user Static route
I1 - ISIS L1, I2 - ISIS L2, IA - ISIS
interarea, IS - ISIS summary
O - OSPF intra, OI - OSPF inter, OE1 -
OSPF ext 1, OE2 - OSPF ext 2
ON1 - OSPF NSSA ext 1, ON2 - OSPF NSSA ext 2
C 2001:3::/64 [0/0]
via ::, Loopback0
L 2001:3::3/128 [0/0]
via ::, Loopback0
C 2001:13::/64 [0/0]
via ::, Serial1/1
L 2001:13::3/128 [0/0]
via ::, Serial1/1
L FE80::/10 [0/0]
via ::, Null0
L FF00::/8 [0/0]
via ::, Null0
R3#
R1#show ipv6
route
IPv6
Routing Table - 8 entries
Codes:
C - Connected, L - Local, S - Static, R - RIP, B - BGP
U - Per-user Static route
I1 - ISIS L1, I2 - ISIS L2, IA - ISIS
interarea, IS - ISIS summary
O - OSPF intra, OI - OSPF inter, OE1 -
OSPF ext 1, OE2 - OSPF ext 2
ON1 - OSPF NSSA ext 1, ON2 - OSPF NSSA
ext 2
R
2001:2::/64 [120/2]
via FE80::C001:6FF:FE48:0, Serial1/0
O
2001:3::3/128 [110/64]
via FE80::C002:6FF:FE48:0, Serial1/1
C 2001:12::/64 [0/0]
via ::, Serial1/0
L 2001:12::1/128 [0/0]
via ::, Serial1/0
C 2001:13::/64 [0/0]
via ::, Serial1/1
L 2001:13::1/128 [0/0]
via ::, Serial1/1
L FE80::/10 [0/0]
via ::, Null0
L FF00::/8 [0/0]
via ::, Null0
R1#
Observation:
·
RIP
is configured between R1-R2
·
R2
has advertised its loopback0 2001:2::2 into RIP and R1 has that RIP route
installed in its routing table
·
OSPF
is configured between R1-R3
·
R3
has advertised its loopback0 2001:3::3 into OSPF and R1 has that OSPF route in
its routing table
Now, let me configure redistribution between RIPng and OSPFv3 in R1:
R1(config)#ipv6
router rip RIPng
R1(config-rtr)#redistribute ospf 1 metric 2
R1(config-rtr)#exit
R1(config)#ipv6
router ospf 1
R1(config-rtr)#redistribute rip RIPng
R1(config-rtr)#
Now, let’s see the Routing tables:
R2#show ipv6 route
IPv6
Routing Table - 7 entries
Codes:
C - Connected, L - Local, S - Static, R - RIP, B - BGP
U - Per-user Static route
I1 - ISIS L1, I2 - ISIS L2, IA - ISIS
interarea, IS - ISIS summary
O
- OSPF intra, OI - OSPF inter, OE1 - OSPF ext 1, OE2 - OSPF ext 2
ON1 - OSPF NSSA ext 1, ON2 - OSPF NSSA
ext 2
C 2001:2::/64 [0/0]
via ::, Loopback0
L 2001:2::2/128 [0/0]
via ::, Loopback0
R
2001:3::3/128 [120/3]
via FE80::C000:6FF:FE48:0, Serial1/0
C 2001:12::/64 [0/0]
via ::, Serial1/0
L 2001:12::2/128 [0/0]
via ::, Serial1/0
L FE80::/10 [0/0]
via ::, Null0
L FF00::/8 [0/0]
via ::, Null0
R2#
R1(config-rtr)#do
show ipv6 route
IPv6
Routing Table - 8 entries
Codes:
C - Connected, L - Local, S - Static, R - RIP, B - BGP
U - Per-user Static route
I1 - ISIS L1, I2 - ISIS L2, IA - ISIS
interarea, IS - ISIS summary
O - OSPF intra, OI - OSPF inter, OE1 -
OSPF ext 1, OE2 - OSPF ext 2
ON1 - OSPF NSSA ext 1, ON2 - OSPF NSSA
ext 2
R 2001:2::/64 [120/2]
via FE80::C001:6FF:FE48:0, Serial1/0
O 2001:3::3/128 [110/64]
via FE80::C002:6FF:FE48:0, Serial1/1
C 2001:12::/64 [0/0]
via ::, Serial1/0
L 2001:12::1/128 [0/0]
via ::, Serial1/0
C 2001:13::/64 [0/0]
via ::, Serial1/1
L 2001:13::1/128 [0/0]
via ::, Serial1/1
L FE80::/10 [0/0]
via ::, Null0
L FF00::/8 [0/0]
via ::, Null0
R1(config-rtr)#
R3#show ipv6
route
IPv6
Routing Table - 7 entries
Codes:
C - Connected, L - Local, S - Static, R - RIP, B - BGP
U - Per-user Static route
I1 - ISIS L1, I2 - ISIS L2, IA - ISIS
interarea, IS - ISIS summary
O - OSPF intra, OI - OSPF inter, OE1 -
OSPF ext 1, OE2 - OSPF ext 2
ON1 - OSPF NSSA ext 1, ON2 - OSPF NSSA
ext 2
OE2
2001:2::/64 [110/20]
via FE80::C000:6FF:FE48:0, Serial1/1
C 2001:3::/64 [0/0]
via ::, Loopback0
L 2001:3::3/128 [0/0]
via ::, Loopback0
C 2001:13::/64 [0/0]
via
::, Serial1/1
L 2001:13::3/128 [0/0]
via ::, Serial1/1
L FE80::/10 [0/0]
via ::, Null0
L FF00::/8 [0/0]
via ::, Null0
R3#
Observation:
·
R2
has R3’s loopback 2001:3::3
·
R2
doesn’t have R1-R3 link, because in IPV6 redistribution step-2 will not happen
by default
·
R3
has R2’s loopback 2001:2::2
·
R3
doesn’t have R1-R2 link, because in IPV6 redistribution step-2 will not happen
by default
·
Solution
is to add include-connected key-word while doing redistribution
R1(config-rtr)#ipv6
router rip RIPng
R1(config-rtr)#redistribute ospf 1 metric 2 include-connected
R1(config-rtr)#exit
R1(config)#ipv6
router ospf 1
R1(config-rtr)#redistribute rip RIPng include-connected
R1(config-rtr)#
·
Now, Let’s see the Routing tables:
R2#show ipv6
route
IPv6
Routing Table - 8 entries
Codes:
C - Connected, L - Local, S - Static, R - RIP, B - BGP
U - Per-user Static route
I1 - ISIS L1, I2 - ISIS L2, IA - ISIS
interarea, IS - ISIS summary
O - OSPF intra, OI - OSPF inter, OE1 -
OSPF ext 1, OE2 - OSPF ext 2
ON1 - OSPF NSSA ext 1, ON2 - OSPF NSSA
ext 2
C 2001:2::/64 [0/0]
via ::, Loopback0
L 2001:2::2/128 [0/0]
via ::, Loopback0
R
2001:3::3/128 [120/3]
via FE80::C000:6FF:FE48:0, Serial1/0
C 2001:12::/64 [0/0]
via ::, Serial1/0
L 2001:12::2/128 [0/0]
via ::, Serial1/0
R
2001:13::/64 [120/3]
via FE80::C000:6FF:FE48:0, Serial1/0
L FE80::/10 [0/0]
via ::, Null0
L FF00::/8 [0/0]
via ::, Null0
R2#
R1(config-rtr)#do
show ipv6 route
IPv6
Routing Table - 8 entries
Codes:
C - Connected, L - Local, S - Static, R - RIP, B - BGP
U - Per-user Static route
I1 - ISIS L1, I2 - ISIS L2, IA - ISIS
interarea, IS - ISIS summary
O - OSPF intra, OI - OSPF inter, OE1 -
OSPF ext 1, OE2 - OSPF ext 2
ON1 - OSPF NSSA ext 1, ON2 - OSPF NSSA
ext 2
R 2001:2::/64 [120/2]
via FE80::C001:6FF:FE48:0, Serial1/0
O 2001:3::3/128 [110/64]
via FE80::C002:6FF:FE48:0, Serial1/1
C 2001:12::/64 [0/0]
via ::, Serial1/0
L 2001:12::1/128 [0/0]
via ::, Serial1/0
C 2001:13::/64 [0/0]
via ::, Serial1/1
L 2001:13::1/128 [0/0]
via ::, Serial1/1
L FE80::/10 [0/0]
via ::, Null0
L FF00::/8 [0/0]
via ::, Null0
R1(config-rtr)#
R3#show ipv6
route
IPv6
Routing Table - 8 entries
Codes:
C - Connected, L - Local, S - Static, R - RIP, B - BGP
U - Per-user Static route
I1 - ISIS L1, I2 - ISIS L2, IA - ISIS
interarea, IS - ISIS summary
O - OSPF intra, OI - OSPF inter, OE1 -
OSPF ext 1, OE2 - OSPF ext 2
ON1 - OSPF NSSA ext 1, ON2 - OSPF NSSA
ext 2
OE2
2001:2::/64 [110/20]
via FE80::C000:6FF:FE48:0, Serial1/1
C 2001:3::/64 [0/0]
via ::, Loopback0
L 2001:3::3/128 [0/0]
via ::, Loopback0
OE2
2001:12::/64 [110/20]
via FE80::C000:6FF:FE48:0, Serial1/1
C 2001:13::/64 [0/0]
via ::, Serial1/1
L 2001:13::3/128 [0/0]
via ::, Serial1/1
L FE80::/10 [0/0]
via ::, Null0
L FF00::/8 [0/0]
via ::, Null0
R3#
Observation:
·
R2
has R3’s loopback 2001:3::3
·
R2
also has R1-R3 link, 2001:13::/64
·
R3
has R2’s loopback 2001:2::2
·
R3
also has R1-R2 link, 2001:12::/64
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