The document describes the configuration of OSPFv3 in a single area network across four routers. Key steps include: 1. Configuring IPv6 unicast routing and interface addresses on each router; 2. Enabling OSPFv3 on each router and assigning a router ID, then configuring interfaces to advertise connected networks; 3. Verification shows each router has established full adjacencies and is exchanging routes, including successful ping from R3 to R4.

1. `
CONFIGURE OSPF V3 SINGLE AREA
ROUTER 1
R1#CONFIG T
Enter configuration commands, one per line. End with CNTL/Z.
R1(config)#
R1(config)#
R1(config)#IPV6 UNI
R1(config)#IPV6 UNIcast-routing
R1(config)#
R1(config)#INT FA 0/0
R1(config-if)#IPV6 ENABLE
R1(config-if)#IPV6 ADD 2001:ABCD:1234::1/126
R1(config-if)#NO SHUT
R1(config-if)#
*Nov 19 00:59:01.199: %LINK-3-UPDOWN: Interface FastEthernet0/0, changed state to up
R1(config-if)#
*Nov 19 00:59:01.199: %ENTITY_ALARM-6-INFO: CLEAR INFO Fa0/0 Physical Port Administrative State Down

2. `
*Nov 19 00:59:02.199: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/0, changed state to up
R1(config-if)#INT FA0/1
R1(config-if)#IPV6 ADD 2FFE:ABCD:1234::1/64
R1(config-if)#NO SHUT
R1(config-if)#
*Nov 19 00:59:43.011: %LINK-3-UPDOWN: Interface FastEthernet0/1, changed state to up
R1(config-if)#
*Nov 19 00:59:43.011: %ENTITY_ALARM-6-INFO: CLEAR INFO Fa0/1 Physical Port Administrative State Down
*Nov 19 00:59:44.011: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1, changed state to up
R1(config-if)#END
R1#R1#COPY RU
R1#COPY RUn ST
R1#COPY RUn STartup-config
Destination filename [startup-config]?
Building configuration...
[OK]
R1#
*Nov 19 00:59:59.235: %SYS-5-CONFIG_I: Configured from console by console
ROUTER 2
R2#CONFIG T
Enter configuration commands, one per line. End with CNTL/Z.
R2(config)#
R2(config)#
R2(config)#IPV6 UNI
R2(config)#IPV6 UNIcast-routing
R2(config)#INT FA 0/0

3. `
R2(config-if)#IPV6 EN
R2(config-if)#IPV6 ENable
R2(config-if)#IPV6 ADD 2001:ABCD:1234::2/126
R2(config-if)#NO SHUT
R2(config-if)#
*Nov 19 01:02:57.755: %LINK-3-UPDOWN: Interface FastEthernet0/0, changed state to up
R2(config-if)#
*Nov 19 01:02:57.755: %ENTITY_ALARM-6-INFO: CLEAR INFO Fa0/0 Physical Port Administrative State Down
*Nov 19 01:02:58.755: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/0, changed state to up
R2(config-if)#
R2(config-if)#INT FA 0/1
R2(config-if)#IPV6 ADD 2007:ABCD:1234::1/64
R2(config-if)#NO SHUT
R2(config-if)#END
R2#
*Nov 19 01:03:49.647: %LINK-3-UPDOWN: Interface FastEthernet0/1, changed state to up
*Nov 19 01:03:49.647: %ENTITY_ALARM-6-INFO: CLEAR INFO Fa0/1 Physical Port Administrative State Down
*Nov 19 01:03:49.835: %SYS-5-CONFIG_I: Configured from console by console
*Nov 19 01:03:50.647: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1, changed state to up
R2#COPY RUN STartup-config
Destination filename [startup-config]?
Building configuration...
[OK]
ROUTER 3
R3#CONFIG T
Enter configuration commands, one per line. End with CNTL/Z.
R3(config)#IPV6 UNI
R3(config)#IPV6 UNIcast-routing

4. `
R3(config)#INT FA 0/1
R3(config-if)#IPV6 EN
R3(config-if)#IPV6 ENable
R3(config-if)#IPV6 ADD 2FFE:ABCD:1234::2/64
R3(config-if)#NO SHUT
R3(config-if)#
*Nov 19 01:05:42.795: %LINK-3-UPDOWN: Interface FastEthernet0/1, changed state to up
R3(config-if)#
*Nov 19 01:05:42.795: %ENTITY_ALARM-6-INFO: CLEAR INFO Fa0/1 Physical Port Administrative State Down
*Nov 19 01:05:43.795: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1, changed state to
R3(config-if)#END
R3#C
*Nov 19 01:05:53.099: %SYS-5-CONFIG_I: Configured from console by console
R3#COPY RUN ST
R3#COPY RUN STartup-config
Destination filename [startup-config]?
Building configuration...
[OK]
ROUTER 4R4#CONFIG T
Enter configuration commands, one per line. End with CNTL/Z.
R4(config)#
R4(config)#IPV6 UNI
R4(config)#IPV6 UNIcast-routing
R4(config)#INT FA 0/1
R4(config-if)#IPV6 EN
R4(config-if)#IPV6 ENable
R4(config-if)#IPV6 ADD 2007:ABCD:1234::2/64
R4(config-if)#NO SHUT

5. `
R4(config-if)#END
R4#
*Nov 19 01:07:04.795: %SYS-5-CONFIG_I: Configured from console by console
*Nov 19 01:07:05.267: %LINK-3-UPDOWN: Interface FastEthernet0/1, changed state to up
R4#
*Nov 19 01:07:05.267: %ENTITY_ALARM-6-INFO: CLEAR INFO Fa0/1 Physical Port Administrative State Down
*Nov 19 01:07:06.267: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1, changed state to up
R4#COPY RUN ST
R4#COPY RUN STartup-config
Destination filename [startup-config]?
Building configuration...
[OK]
CONFIGURING OSPF
R1
R1#CONFIG T
Enter configuration commands, one per line. End with CNTL/Z.
R1(config)#
R1(config)#IPV6 ROUTER OSPF 1
R1(config-rtr)#
*Nov 19 01:10:04.751: %OSPFv3-4-NORTRID: OSPFv3 process 1 could not pick a router-id,
please configure manually
R1(config-rtr)#ROuter-id 1.1.1.1
R1(config-rtr)#END

6. `
R1(config)#
R1(config)#INT FA 0/0
R1(config-if)#IPV6 OSPF 1 AREA 0
R1(config-if)#NO SHUT
R1(config-if)#
R1(config-if)#
R1(config-if)#INT FA 0/1
R1(config-if)#IPV6 ENA
R1(config-if)#IPV6 ENAble
R1(config-if)#IPV6 OSPF 1 AREA 0
R1(config-if)#NO SHUT
R1(config-if)#
R2#CONFIG T
Enter configuration commands, one per line. End with CNTL/Z.
R2(config)#
R2(config)#IPV6 ROUTER OSPF 1
R2(config-rtr)#R
*Nov 19 01:13:01.391: %OSPFv3-4-NORTRID: OSPFv3 process 1 could not pick a router-id,
please configure manually
R2(config-rtr)#ROUTER-id 2.2.2.2
R2(config-rtr)#INT FA 0/0
R2(config-if)#IPV6 ENA
R2(config-if)#IPV6 ENAble
R2(config-if)#IPV6 OSPF 1 AREA 0
R2(config-if)#

7. `
*Nov 19 01:13:45.067: %OSPFv3-5-ADJCHG: Process 1, Nbr 1.1.1.1 on FastEthernet0/0 from LOADING to FULL, Loading Done
R2(config-if)#
*Nov 19 01:13:45.555: %OSPFv3-4-ERRRCV: Received invalid packet: Bad Checksum from FE80::C800:EFF:FEBC:8, FastEthernet0/0
R2(config-if)#INT FA 0/1
R2(config-if)#IPV6 OSPF 1 AREA 0
R2(config-if)#NO SHUT
R2(config-if)#
R2(config-if)#END
R2#
*Nov 19 01:14:10.803: %SYS-5-CONFIG_I: Configured from console by console
R2#R1(config-if)#END
R3#
R3#CONFIG T
Enter configuration commands, one per line. End with CNTL/Z.
R3(config)#
R3(config)#
R3(config)#IPV6 ROUTER OSPF 1
R3(config-rtr)#R
*Nov 19 01:15:47.547: %OSPFv3-4-NORTRID: OSPFv3 process 1 could not pick a router-id,
please configure manually
R3(config-rtr)#ROUT
R3(config-rtr)#ROUTer-id 3.3.3.3
R3(config-rtr)#INT FA 0/1
R3(config-if)#IPV6 EN
R3(config-if)#IPV6 ENable
R3(config-if)#IPV6 OSPF 1 AREA 0
R3(config-if)#NO

8. `
*Nov 19 01:16:12.199: %OSPFv3-4-ERRRCV: Received invalid packet: Bad Checksum from FE80::C800:EFF:FEBC:6, FastEthernet0/1
R3(config-if)#NO SHUT
R3(config-if)#
R3(config-if)#END
R3#
R3#
*Nov 19 01:16:16.287: %SYS-5-CONFIG_I: Configured from console by console
*Nov 19 01:16:17.135: %OSPFv3-5-ADJCHG: Process 1, Nbr 1.1.1.1 on FastEthernet0/1 from LOADING to FULL, Loading Done
ROUTER 4
R4#CONFIG T
Enter configuration commands, one per line. End with CNTL/Z.
R4(config)#
R4(config)#
R4(config)#IPV6 ROUTER OSPF 1
R4(config-rtr)#RO
*Nov 19 01:16:58.167: %OSPFv3-4-NORTRID: OSPFv3 process 1 could not pick a router-id,
please configure manually
R4(config-rtr)#ROU
R4(config-rtr)#ROUter-id 4.4.4.4
R4(config-rtr)#INT FA 0/1
R4(config-if)#IPV6 OSPF 1 AREA 0
R4(config-if)#NO SHU
*Nov 19 01:17:14.979: %OSPFv3-5-ADJCHG: Process 1, Nbr 2.2.2.2 on FastEthernet0/1 from LOADING to FULL, Log Done
R4(config-if)#NO SHUT
R4(config-if)#END
R4#
*Nov 19 01:17:20.615: %SYS-5-CONFIG_I: Configured from console by console

9. `
VERIFY OSPF
R1
R1#SHOW IPV6 OSPF NEIghbor
Neighbor ID Pri State Dead Time Interface ID Interface
3.3.3.3 1 FULL/BDR 00:00:35 5 FastEthernet0/1
2.2.2.2 1 FULL/BDR 00:00:36 4 FastEthernet0/0
* FROM R1 U CAN SEE UR NEIGHBOR R2 AND R3
R1#
R1#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:ABCD:1234::/126 [0/0]
via ::, FastEthernet0/0
L 2001:ABCD:1234::1/128 [0/0]
via ::, FastEthernet0/0
O 2007:ABCD:1234::/64 [110/2]
via FE80::C801:EFF:FEBC:8, FastEthernet0/0
C 2FFE:ABCD:1234::/64 [0/0]
via ::, FastEthernet0/1
L 2FFE:ABCD:1234::1/128 [0/0]
via ::, FastEthernet0/1
L FE80::/10 [0/0]
via ::, Null0

10. `
L FF00::/8 [0/0]
via ::, Null0
FRM R1 U CAN SEE THE OSPF WAS ESTABLISH WITH CHARATER 0 (OSPF)
TESTING BY PINGING FROM R3 TO R4 SUCCESSFULLY
R3#ping 2007:abcd:1234::2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 2007:ABCD:1234::2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 60/112/172 ms
ANOTHER COMMAND TO VERIFY OSPF
R1#show ipv6 ospf database
OSPFv3 Router with ID (1.1.1.1) (Process ID 1)
Router Link States (Area 0)
ADV Router Age Seq# Fragment ID Link count Bits
1.1.1.1 170 0x80000006 0 2 None
2.2.2.2 107 0x80000005 0 2 None
3.3.3.3 166 0x80000002 0 1 None
4.4.4.4 100 0x80000002 0 1 None
Net Link States (Area 0)
ADV Router Age Seq# Link ID Rtr count
1.1.1.1 319 0x80000001 4 2
1.1.1.1 170 0x80000001 5 2
2.2.2.2 107 0x80000001 5 2

11. `
Link (Type-8) Link States (Area 0)
ADV Router Age Seq# Link ID Interface
1.1.1.1 455 0x80000001 5 Fa0/1
3.3.3.3 171 0x80000001 5 Fa0/1
1.1.1.1 497 0x80000001 4 Fa0/0
2.2.2.2 327 0x80000001 4 Fa0/0
Intra Area Prefix Link States (Area 0)
ADV Router Age Seq# Link ID Ref-lstype Ref-LSID
1.1.1.1 326 0x80000001 4096 0x2002 4
1.1.1.1 177 0x80000001 5120 0x2002 5
2.2.2.2 114 0x80000001 5120 0x2002 5
R1#