**IPv6 Route Redistribution**
Route redistribution in IPv6 allows different routing
protocols (e.g., OSPFv3, EIGRP for IPv6, BGP, RIPng, IS-IS) to exchange routing
information within the same network. This is useful in multi-vendor or
multiprotocol environments where migration or integration is required.
**Key Points:**
- Redistribution is typically configured on routers that run
multiple routing protocols.
- Careful planning is needed to avoid routing loops,
suboptimal paths, or convergence issues.
- Use route filtering, metrics, and administrative distance
tuning to control redistribution.
- Default metrics often need manual assignment when
redistributing between protocols (e.g., OSPF to EIGRP).
**Example Use Case:**
Connecting an OSPFv3 domain with a BGP IPv6 network,
allowing internal routes to be advertised externally and vice versa.
**Configuration Note:**
Always verify routes after redistribution and ensure prefix
lengths and next-hop addresses are correctly advertised.
Let's see the configuration:-
Task:
- Configure the topology as per the diagram
- Configure the IPv6 addresses as per the topology
- Configure EIGRPv3 on router 1 and advertise directly
- Configure OSPFv3 on router 2 and advertise FastEthernet 2/0 - 3/0
- Configure EIGRPv3 on router 2 and advertise FastEthernet 0/0
- Configure OSPFv3 on router 3 and advertise FastEthernet 3/0
- Configure RIPng on router 3 and advertise FastEthernet 2/0
- Configure redistribution between EIGRPv3 and OSPFv3 and vice versa
- Configure redistribution between RIPng and OSPFv3 and vice versa
- Make sure all the routes are exchanged
- ensure the connectivity and verify with show commands
R1(config)#ipv6
unicast-routing
R1(config)#interface
fastethernet 0/0
R1(config-if)#ipv6
address 2001:1122:1122:1122::1/64
R1(config-if)#no
shutdown
R1(config-if)#exit
R1(config)#interface
fastethernet 2/0
R1(config-if)#ipv6
address fc00:1111:1111:1111::1/64
R1(config-if)#no
shutdown
R1(config-if)#no
keepalive
R1(config-if)#exit
R1(config)#
R2(config)#ipv6
unicast-routing
R2(config)#interface
fastethernet 0/0
R2(config-if)#ipv6
address 2001:1122:1122:1122::2/64
R2(config-if)#no
shutdown
R2(config-if)#exit
R2(config)#interface
fastethernet 2/0
R2(config-if)#ipv6
address fc00:2222:2222:2222::1/64
R2(config-if)#no
shutdown
R2(config-if)#no
keepalive
R2(config-if)#exit
R2(config)#interface
fastethernet 3/0
R2(config-if)#ipv6
address 2001:2233:2233:2233::1/64
R2(config-if)#no
shutdown
R2(config-if)#exit
R3#show ipv6 interface brief
FastEthernet0/0 [administratively down/down]
unassigned
ATM1/0 [administratively down/down]
unassigned
FastEthernet2/0 [up/up]
FE80::C803:A5FF:FE68:38
FC00:3333:3333:3333::1
FastEthernet3/0 [up/up]
FE80::C803:A5FF:FE68:54
2001:2233:2233:2233::2
R1(config)#ipv6 router eigrp 65100
R1(config-rtr)#no shutdown
R1(config-rtr)#router-id 11.11.11.11
R1(config-rtr)#exit
R1(config)#interface fastethernet 0/0
R1(config-if)#ipv6 eigrp 65100
R1(config-if)#exit
R1(config)#interface fastethernet 2/0
R1(config-if)#ipv6 eigrp 65100
R1(config-if)#exit
R2(config)#ipv6 router eigrp 65100
R2(config-rtr)#no shutdown
R2(config-rtr)#router-id 22.22.22.22
R2(config-rtr)#exit
R2(config)#interface fastethernet 0/0
R2(config-if)#ipv6 eigrp 65100
R2(config-if)#exit
R2(config)#IPv6 router ospf 100
R2(config-rtr)#router-id 22.22.22.22
R2(config-rtr)#exit
R2(config)#interface fastethernet 2/0
R2(config-if)#ipv6 ospf 100 area 0
R2(config-if)#exit
R2(config)#interface fastethernet 3/0
R2(config-if)#ipv6 ospf 100 area 0
R2(config-if)#exit
R3(config)#IPv6 router ospf 100
R3(config-rtr)#router-id 33.33.33.33
R3(config-rtr)#exit
R3(config)#interface fastethernet 3/0
R3(config-if)#ipv6 ospf 100 area 0
R3(config-if)#exit
R3(config)#ipv6 unicast-routing
R3(config)#interface fastEthernet 2/0
R3(config-if)#ipv6 rip internetworks enable
R3(config-if)#exit
R2(config)#ipv6 router ospf 100
R2(config-rtr)#redistribute eigrp 65100 metric 100 metric-type 1 include-connected
R2(config-rtr)#exit
R2(config)#ipv6 router eigrp 65100
R2(config-rtr)#redistribute ospf 100 include-connected metric 1000 2000 255 1 1500
metric <bw> <delay> <reliability> <load> <mtu>R2(config-rtr)#exit
R3(config)#ipv6 router ospf 100
R3(config-rtr)#redistribute rip internetworks include-connected metric 100 metric-type 1
R3(config-rtr)#exit
R1#show ipv6 route
IPv6 Routing Table - Default - 8 entries
Codes: C - Connected, L - Local, S - Static, U - Per-user Static route
B - BGP, M - MIPv6, R - RIP, I1 - ISIS L1
I2 - ISIS L2, IA - ISIS interarea, IS - ISIS summary, D - EIGRP
EX - EIGRP external
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 2001:1122:1122:1122::/64 [0/0]
via FastEthernet0/0, directly connected
L 2001:1122:1122:1122::1/128 [0/0]
via FastEthernet0/0, receive
EX 2001:2233:2233:2233::/64 [170/3074560]
via FE80::C802:59FF:FE98:0, FastEthernet0/0
C FC00:1111:1111:1111::/64 [0/0]
via FastEthernet2/0, directly connected
L FC00:1111:1111:1111::1/128 [0/0]
via FastEthernet2/0, receive
EX FC00:2222:2222:2222::/64 [170/3074560]
via FE80::C802:59FF:FE98:0, FastEthernet0/0
EX FC00:3333:3333:3333::/64 [170/3074560]
via FE80::C802:59FF:FE98:0, FastEthernet0/0
L FF00::/8 [0/0]
via Null0, receive
R2#show ipv6 protocol
IPv6 Routing Protocol is "connected"
IPv6 Routing Protocol is "eigrp 65100"
EIGRP metric weight K1=1, K2=0, K3=1, K4=0, K5=0
EIGRP maximum hopcount 100
EIGRP maximum metric variance 1
Interfaces:
FastEthernet0/0
Redistribution:
Redistributing protocol ospf 100 with metric 0 include-connected
Maximum path: 16
Distance: internal 90 external 170
IPv6 Routing Protocol is "ospf 100"
Interfaces (Area 0):
FastEthernet3/0
FastEthernet2/0
Redistribution:
Redistributing protocol eigrp 65100 with metric 100 type 1 include-connected
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