Advanced CCIE Routing & Switching v5.0 www.MicronicsTraining.com Narbik Kocharians CCSI, CCIE #12410 R&S, Security, SP VOL-III CCIE R&S by Narbik Kocharians Advanced CCIE R&S Work Book 5.0 © 2015 Narbik Kocharians. All rights reserved Page 1 of 24 Lab 3 – OSPF Broadcast Networks Lo0 2::2/64 Lo0 1::1/64 :2 :1 R2 R1 F0/0 F0/0 10::/64 Lo0 7::7/64 G0/0 Lo0 8::8/64 G0/0 :8 :7 R8 R7 Task 1 Configure the routers based on the above topology, DO NOT configure any routing protocol. If this configuration is performed properly, these routers should be able to ping their directly connected routers. The Link-local IPv6 address of the routers should be set to fe80::1, fe80::2, fe80::7 and fe80::8 for routers R1, R2, R7 and R8 respectively. On SW1: SW1(config)#int range f0/1-2 , f0/7-8 SW1(config-if-range)#Swi mode acc SW1(config-if-range)#Swi acc vl 100 SW1(config-if-range)#Spanning portf SW1(config-if-range)#No shut On R1: R1(config)#int f0/0 CCIE R&S by Narbik Kocharians Advanced CCIE R&S Work Book 5.0 © 2015 Narbik Kocharians. All rights reserved Page 2 of 24 R1(config-if)#ipv6 address 10::1/64 R1(config-if)#ipv6 address fe80::1 Link-local R1(config-if)#No shut R1(config)#int lo0 R1(config-if)#ipv6 address 1::1/64 On R2: R2(config)#int f0/0 R2(config-if)#ipv6 address 10::2/64 R2(config-if)#ipv6 address fe80::2 Link-local R2(config-if)#No shut R2(config)#int lo0 R2(config-if)#ipv6 address 2::2/64 On R7: R7(config)#int g0/0 R7(config-if)#ipv6 address 10::7/64 R7(config-if)#ipv6 address fe80::7 Link-local R7(config-if)#No shut R7(config)#int lo0 R7(config-if)#ipv6 address 7::7/64 On R8: R8(config)#int g0/0 R8(config-if)#ipv6 address 10::8/64 R8(config-if)#ipv6 address fe80::8 Link-local R8(config-if)#No shut R8(config)#int lo0 R8(config-if)#ipv6 address 8::8/64 To verify the configuration: On R1: R1#Ping 10::2 Type escape sequence to abort. CCIE R&S by Narbik Kocharians Advanced CCIE R&S Work Book 5.0 © 2015 Narbik Kocharians. All rights reserved Page 3 of 24 Sending 5, 100-byte ICMP Echos to 10::2, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 0/1/4 ms R1#Ping 10::7 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 10::7, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 0/0/4 ms R1#Ping 10::8 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 10::8, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 0/1/8 ms Task 2 Configure OSPF area 0 on all routers and run their directly connected interfaces. Ensure that loopback interfaces are advertised with their correct mask. You should configure 0.0.0.1, 0.0.0.2, 0.0.0.7 and 0.0.0.8 as the router IDs of R1, R2, R7 and R8 respectively. R7 and R8 should use an address-family to accomplish this task. R7 should be the DR for this segment. On All Routers: Rx(config)#ipv6 unicast-routing Rx(config-router)#int lo0 Rx(config-if)#ipv6 ospf network point-to-point On R1: R1(config)#ipv6 router ospf 1 R1(config-rtr)#router-id 0.0.0.1 R1(config)#int f0/0 R1(config-if)#ipv6 ospf 1 area 0 CCIE R&S by Narbik Kocharians Advanced CCIE R&S Work Book 5.0 © 2015 Narbik Kocharians. All rights reserved Page 4 of 24 R1(config-if)#int lo0 R1(config-if)#ipv6 ospf 1 area 0 On R2: R2(config)#ipv6 router ospf 1 R2(config-rtr)#router-id 0.0.0.2 R2(config)#int f0/0 R2(config-if)#ipv6 ospf 1 are 0 R2(config-if)#int lo0 R2(config-if)#ipv6 ospf 1 are 0 You should see the following console message: %OSPFv3-5-ADJCHG: Process 1, Nbr 0.0.0.1 on FastEthernet0/0 from LOADING to FULL, Loading Done On R7: R7(config)#router ospfv3 1 R7(config-router)#address-family ipv6 unicast R7(config-router-af)#router-id 0.0.0.7 Just like OSPFv2 the router with the highest priority will be elected as the DR for that given segment, that’s if all the routers on that given segment come up at the same time. But if the priority of all routers are the same the tie breaker is the router-id, this means that the router with the highest router-id will win the DR election. R7(config)#int g0/0 R7(config-if)#ospfv3 1 ipv6 area 0 R7(config-if)#ospfv3 priority 2 R7(config-if)#int lo0 R7(config-if)#ospfv3 1 ipv6 area 0 You should see the following console message: %OSPFv3-5-ADJCHG: Process 1, IPv6, Nbr 0.0.0.1 on GigabitEthernet0/0 from LOADING to FULL, Loading Done %OSPFv3-5-ADJCHG: Process 1, IPv6, Nbr 0.0.0.2 on GigabitEthernet0/0 from LOADING to FULL, Loading Done CCIE R&S by Narbik Kocharians Advanced CCIE R&S Work Book 5.0 © 2015 Narbik Kocharians. All rights reserved Page 5 of 24 On R8: R8(config)#router ospfv3 1 R8(config-router)#address-family ipv6 unicast R8(config-router-af)#router-id 0.0.0.8 R8(config-if)#int G0/0 R8(config-if)#ospfv3 1 ipv6 area 0 R8(config-if)#int lo0 R8(config-if)#ospfv3 1 ipv6 area 0 You should see the following console message: %OSPFv3-5-ADJCHG: Process 1, IPv6, Nbr 0.0.0.1 on GigabitEthernet0/0 from LOADING to FULL, Loading Done %OSPFv3-5-ADJCHG: Process 1, IPv6, Nbr 0.0.0.2 on GigabitEthernet0/0 from LOADING to FULL, Loading Done To ensure that R7 is the DR, we need to clear ip ospf process on all routers: R8#Clear ipv6 ospf process Reset selected OSPFv3 processes? [no]: y To verify the configuration: On R1: R1#Show ipv6 route ospf IPv6 Routing Table - default - 8 entries Codes: C - Connected, L - Local, S - Static, U - Per-user Static route B - BGP, HA - Home Agent, MR - Mobile Router, R - RIP I1 - ISIS L1, I2 - ISIS L2, IA - ISIS interarea, IS - ISIS summary D - EIGRP, EX - EIGRP external, NM - NEMO, ND - Neighbor Discovery l - LISP O - OSPF Intra, OI - OSPF Inter, OE1 - OSPF ext 1, OE2 - OSPF ext 2 ON1 - OSPF NSSA ext 1, ON2 - OSPF NSSA ext 2 O O O 2::/64 [110/2] via FE80::2, FastEthernet0/0 7::/64 [110/2] via FE80::7, FastEthernet0/0 8::/64 [110/2] via FE80::8, FastEthernet0/0 CCIE R&S by Narbik Kocharians Advanced CCIE R&S Work Book 5.0 © 2015 Narbik Kocharians. All rights reserved Page 6 of 24 R1#Show ipv6 ospf database network OSPFv3 Router with ID (0.0.0.1) (Process ID 1) Net Link States (Area 0) LS age: 63 Options: (V6-Bit, E-Bit, R-bit, DC-Bit) LS Type: Network Links Link State ID: 3 (Interface ID of Designated Router) Advertising Router: 0.0.0.7 LS Seq Number: 80000003 Checksum: 0xDD05 Length: 40 Attached Router: 0.0.0.7 Attached Router: 0.0.0.1 Attached Router: 0.0.0.2 Attached Router: 0.0.0.8 We can see that it’s the DR that floods LSA Type 2s, and on this segment R7 is the DR with a router-id of 0.0.0.7; DR is the only router that is responsible for flooding Network LSAs or LSA Type-2s. We can also see that Network LSAs also reveal the router IDs of all routers that are attached to this Broadcast Multiaccess network. On R8: R8#Show ospfv3 neighbor OSPFv3 1 address-family ipv6 (router-id 0.0.0.8) Neighbor ID 0.0.0.1 0.0.0.2 0.0.0.7 Pri 1 1 2 State FULL/DROTHER FULL/DROTHER FULL/DR Dead Time 00:00:35 00:00:35 00:00:38 Interface ID 3 3 3 Interface GigabitEthernet0/0 GigabitEthernet0/0 GigabitEthernet0/0 R8#Show ospfv3 data network OSPFv3 1 address-family ipv6 (router-id 0.0.0.8) Net Link States (Area 0) LS age: 536 Options: (V6-Bit, E-Bit, R-bit, DC-Bit) LS Type: Network Links Link State ID: 3 (Interface ID of Designated Router) CCIE R&S by Narbik Kocharians Advanced CCIE R&S Work Book 5.0 © 2015 Narbik Kocharians. All rights reserved Page 7 of 24 Advertising Router: 0.0.0.7 LS Seq Number: 80000003 Checksum: 0xDD05 Length: 40 Attached Router: 0.0.0.7 Attached Router: 0.0.0.1 Attached Router: 0.0.0.2 Attached Router: 0.0.0.8 Based on the output of the following show command we can see that hellos are exchanged every 10 seconds and the dead interval is set to 40 seconds: R8#Show ospfv3 int g0/0 | Inc Timer Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5 Let’s see the destination address of OSPF hello messages on OSPF Broadcast network types: R8#Debug ospfv3 hello OSPFv3 hello debugging is on for process 1, IPv6, Default vrf OSPFv3-1-IPv6 HELLO Gi0/0: Send hello to FF02::5 area 0 from FE80::8 interface ID 3 We can see that the hello messages are sent to a Multicast group address of FF02::5, this means that the G0/0 interface of R8 must have joined this Multicast address, let’s see this information: R8#Show ipv6 interface g0/0 | Inc FF FF02::1 FF02::2 FF02::5 FF02::6 FF02::FB FF02::1:FF00:8 We can see that R8 has joined many Multicast groups, let’s explain these groups: FF02::1 – All nodes within the local segment FF02::2 – All routers within the local segment, the local router will only join this group if the “IPv6 unicast-routing” command is configured. FF02::5, and FF02::6 – These are OSPF groups, ::5 is all OSPF routers and ::6 is the DR/BDR. R7 is the DR on this segment, but R8 is the BDR and this is why it has joined this group. FF02::FB – This is the mDNS CCIE R&S by Narbik Kocharians Advanced CCIE R&S Work Book 5.0 © 2015 Narbik Kocharians. All rights reserved Page 8 of 24 FF02::1:FF00:8 – The Solicited Node Multicast group. R1#Undebug all All possible debugging has been turned off Let’s identify the major points of an OSPF Broadcast Network type: Ethernet Networks default to OSPF Broadcast Network types. The timers are 10/40, meaning that the Hello interval is 10 seconds and the dead interval is set to 40 seconds. Next hop does NOT change. In the output of the above “Show ipv6 route ospf” command we can see that the next hop IP address is the IP address of the F0/0 or the G0/0 interface of the router that originated the route. DR and optionally BDR election will take place in Broadcast Multiaccess networks such as Ethernet. In Broadcast network types the hellos are sent to Multicast destination of FF02::5. Task 2 Lab Setup: To copy and paste the initial configurations, go to “Advanced-init” “IPv6” “OSPFv3” Lab-3-Task-2. CCIE R&S by Narbik Kocharians Advanced CCIE R&S Work Book 5.0 © 2015 Narbik Kocharians. All rights reserved Page 9 of 24 Lo0 1::1/64 .1 R1 F0/0 AREA 0 DMVPN 10::/64 :8 F0/0 G0/0 R8 8::8/64 Lo0 .2 G0/0 R2 :7 R7 2::2/64 Lo0 7::7/64 Lo0 Configure OSPFv3 on the tunnel and Loopback 0 interfaces of all routers based on the following policy: R1 is the hub and R2, R7, and R8 are configured as spokes, DO NOT change the topology. Configure the tunnel interfaces of all routers to be OSPFv3 broadcast network type. The Loopback interfaces should be advertised with their correct mask. Configure the router-IDs of the routers to be 0.0.0.1, 0.0.0.2, 0.0.0.7, and 0.0.0.8 for R1, R2, R7 and R8 respectively. The DMVPN network is configured, if you need to change the DMVPN network, DO NOT configure it using dynamic mapping. Before we configure OSPFv3 let’s see if we have reachability to the tunnel IPv6 addresses: On R1: CCIE R&S by Narbik Kocharians Advanced CCIE R&S Work Book 5.0 © 2015 Narbik Kocharians. All rights reserved Page 10 of 24 R1#Ping 10::2 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 10::2, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 0/1/4 ms R1#Ping 10::7 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 10::7, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 0/1/4 ms R1#Ping 10::8 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 10::8, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 0/1/4 ms On All Routers: Rx(config)#IPv6 unicast-routing On R1: To see the interface ID of the tunnel: R1#Show ipv6 inter br | B Tunne Tunnel1 FE80::1 10::1 [up/up] R1(config)#ipv6 router ospf 1 R1(config-rtr)#router-id 0.0.0.1 R1(config)#int lo0 R1(config-if)#ipv6 ospf 1 area 0 R1(config-if)#ipv6 ospf network point-to-point R1(config-if)#int tunnel 1 R1(config-if)#ipv6 ospf 1 area 0 R1(config-if)#ipv6 ospf network broadcast CCIE R&S by Narbik Kocharians Advanced CCIE R&S Work Book 5.0 © 2015 Narbik Kocharians. All rights reserved Page 11 of 24 On R2: R2#Show ipv6 inter br | B Tunne Tunnel2 FE80::2 10::2 [up/up] R2(config)#ipv6 router ospf 1 R2(config-rtr)#router-id 0.0.0.2 R2(config)#int tunnel 2 R2(config-if)#ipv6 ospf 1 area 0 R2(config-if)#ipv6 ospf network broadcast R2(config)#int lo0 R2(config-if)#ipv6 ospf 1 area 0 R2(config-if)#ipv6 ospf network point-to-point On R7: R7#Show ipv6 inter bri | B Tunne Tunnel7 FE80::7 10::7 [up/up] R7(config)#router ospfv3 1 R7(config-router)#address-family ipv6 unicast R7(config-router-af)#router-id 0.0.0.7 R7(config)#int lo0 R7(config-if)#ospfv3 1 ipv6 area 0 R7(config-if)#ospfv3 network point-to-point R7(config)#int tunn 7 R7(config-if)#ospfv3 1 ipv6 area 0 R7(config-if)#ospfv3 network broadcast On R8: R8#Show ipv6 inter br | B Tunnel Tunnel8 [up/up] CCIE R&S by Narbik Kocharians Advanced CCIE R&S Work Book 5.0 © 2015 Narbik Kocharians. All rights reserved Page 12 of 24 FE80::8 10::8 R8(config)#router ospfv3 1 R8(config-router)#address-family ipv6 unicast R8(config-router-af)#router-id 0.0.0.7 R8(config)#int lo0 R8(config-if)#ospfv3 1 ipv6 area 0 R8(config-if)#ospfv3 network point-to-point R8(config-if)#int tunnel 8 R8(config-if)#ospfv3 1 ipv6 area 0 R8(config-if)#ospfv3 network broadcast To verify the configuration: On R1: R1#Show ipv6 ospf neighbor R1# We can see that the routers did not establish an OSPFv3 adjacency. We know that in OSPF Broadcast Network types the Hellos are sent to destination Multicast address of FF02::5, since we have configured OSPFv3 on a NBMA network (DMVPN), let’s check and see if we provided Multicast capability: On R1: R1#Show run int tunnel 1 | B interface interface Tunnel1 no ip address no ip redirects ipv6 address FE80::1 link-local ipv6 address 10::1/64 ipv6 nhrp map 10::8/128 192.1.8.8 ipv6 nhrp map 10::7/128 192.1.7.7 ipv6 nhrp map 10::2/128 192.1.2.2 ipv6 nhrp network-id 111 ipv6 ospf network broadcast ipv6 ospf 1 area 0 tunnel source FastEthernet0/0 tunnel mode gre multipoint end CCIE R&S by Narbik Kocharians Advanced CCIE R&S Work Book 5.0 © 2015 Narbik Kocharians. All rights reserved Page 13 of 24 Based on the above output, we can see that Multicast is NOT mapped, let’s check R2: On R2: R2#Show run int tunnel 2 | B interface interface Tunnel2 no ip address no ip redirects ipv6 address FE80::2 link-local ipv6 address 10::2/64 ipv6 nhrp map 10::1/128 192.1.1.1 ipv6 nhrp network-id 222 ipv6 ospf network broadcast ipv6 ospf 1 area 0 tunnel source FastEthernet0/0 tunnel mode gre multipoint end Actually we can see two problems in the above configuration, the first problem is that the configuration does not provide support for Multicast traffic. The second problem is that the wrong IPv6 address is mapped to the NBMA-IP. In IPv6, the routing protocols use the link local IPv6 address to establish adjacency, but the output of the above show command reveals that the actual IPv6 address is mapped to the NBMA-IP and not the link-local IPv6 address. Let’s provide Multicast capability to R1 and R2’s Tunnel interface. To provide Multicast capability, we need to map Multicast to the NBMA-IP address, the NBMA-IP is the IP address of the tunnel source. On R1: R1#Show run int f0/0 | Inc ip address ip address 192.1.1.1 255.255.255.0 On R2: R2#Show run int f0/0 | Inc ip address ip address 192.1.2.2 255.255.255.0 On R1: R1(config)#Int tunnel 1 R1(config-if)#ipv6 nhrp map multicast 192.1.2.2 CCIE R&S by Narbik Kocharians Advanced CCIE R&S Work Book 5.0 © 2015 Narbik Kocharians. All rights reserved Page 14 of 24 On R2: R2(config)#Int tunnel 2 R2(config-if)#ipv6 nhrp map multicast 192.1.1.1 Now, let’s map the correct IPv6 address to the NBMA-IP: On R1: R1(config)#Int tunnel 1 R1(config-if)#No ipv6 nhrp map 10::2/128 192.1.2.2 R1(config-if)#ipv6 nhrp map fe80::2/128 192.1.2.2 On R2: R2(config)#int tunn 2 R2(config-if)#No ipv6 nhrp map 10::1/128 192.1.1.1 R2(config-if)#ipv6 nhrp map fe80::1/128 192.1.1.1 You should see the following console message: %OSPFv3-5-ADJCHG: Process 1, Nbr 0.0.0.2 on Tunnel1 from LOADING to FULL, Loading Done To verify the configuration: On R1: R1#Show ipv6 route ospf IPv6 Routing Table - default - 6 entries Codes: C - Connected, L - Local, S - Static, U - Per-user Static route B - BGP, HA - Home Agent, MR - Mobile Router, R - RIP I1 - ISIS L1, I2 - ISIS L2, IA - ISIS interarea, IS - ISIS summary D - EIGRP, EX - EIGRP external, NM - NEMO, ND - Neighbor Discovery l - LISP O - OSPF Intra, OI - OSPF Inter, OE1 - OSPF ext 1, OE2 - OSPF ext 2 ON1 - OSPF NSSA ext 1, ON2 - OSPF NSSA ext 2 O 2::/64 [110/1001] via FE80::2, Tunnel1 Let’s fix the configuration of the hub (R1) for the other spokes (R7, and R8): On R1: CCIE R&S by Narbik Kocharians Advanced CCIE R&S Work Book 5.0 © 2015 Narbik Kocharians. All rights reserved Page 15 of 24 R1(config)#int tunn 1 R1(config-if)#No ipv6 nhrp map 10::8/128 192.1.8.8 R1(config-if)#No ipv6 nhrp map 10::7/128 192.1.7.7 R1(config-if)#ipv6 nhrp map fe80::7/128 192.1.7.7 R1(config-if)#ipv6 nhrp map fe80::8/128 192.1.8.8 R1(config-if)#ipv6 nhrp map multicast 192.1.7.7 R1(config-if)#ipv6 nhrp map multicast 192.1.8.8 On R7: R7(config)#int tunn 7 R7(config-if)#No ipv6 nhrp map 10::1/128 192.1.1.1 R7(config-if)#ipv6 nhrp map fe80::1/128 192.1.1.1 R7(config-if)#ipv6 nhrp map multicast 192.1.1.1 You should see the following console message: %OSPFv3-5-ADJCHG: Process 1, IPv6, Nbr 0.0.0.1 on Tunnel7 from LOADING to FULL, Loading Done On R8: R8(config)#int tun 8 R8(config-if)#No ipv6 nhrp map 10::1/128 192.1.1.1 R8(config-if)#ipv6 nhrp map fe80::1/128 192.1.1.1 R8(config-if)#ipv6 nhrp map multicast 192.1.1.1 You should see the following console message: %OSPFv3-5-ADJCHG: Process 1, IPv6, Nbr 0.0.0.1 on Tunnel7 from LOADING to FULL, Loading Done To verify the configuration: On R1: R1#Show ipv6 ospf neighbor Neighbor ID 0.0.0.2 0.0.0.7 0.0.0.8 Pri 1 1 1 State FULL/DROTHER FULL/DROTHER FULL/DR CCIE R&S by Narbik Kocharians Dead Time 00:00:32 00:00:37 00:00:32 Interface ID 23 9 9 Advanced CCIE R&S Work Book 5.0 © 2015 Narbik Kocharians. All rights reserved Interface Tunnel1 Tunnel1 Tunnel1 Page 16 of 24 We can see that R8 which happens to be one of the spokes is the DR, we should always configure the hub router as the DR, let’s configure this and verify: On R2: R2(config)#int tunn 2 R2(config-if)#ipv6 ospf priority 0 To verify the configuration: R2#Show ipv6 ospf interface tunne 2 | inc Pri Transmit Delay is 1 sec, State DROTHER, Priority 0 On R7: R7(config)#int tunn 7 R7(config-if)#ospfv3 priority 0 To verify the configuration: R7#Sh ospfv3 inter tunn 7 | in Pri Transmit Delay is 1 sec, State DROTHER, Priority 0 On R8: R8(config)#int tunn 8 R8(config-if)#ipv6 ospf priority 0 To verify the configuration: R8#Sh ospfv3 inter tunn 8 | in Pri Transmit Delay is 1 sec, State DROTHER, Priority 0 We need to clear the OSPF process for the changes to take affect: On R2: R2#Clear ipv6 ospf process Reset ALL OSPF processes? [no]: Y CCIE R&S by Narbik Kocharians Advanced CCIE R&S Work Book 5.0 © 2015 Narbik Kocharians. All rights reserved Page 17 of 24 On R7 and R8: Rx#Clear ospfv3 process Reset selected OSPFv3 processes? [no]: Y To verify the configuration: On R8: R8#Show ospfv3 neighbor OSPFv3 1 address-family ipv6 (router-id 0.0.0.8) Neighbor ID 0.0.0.1 Pri 1 State FULL/DR Dead Time 00:00:30 Interface ID 23 Interface Tunnel8 R8#Show ipv6 route ospf IPv6 Routing Table - default - 8 entries Codes: C - Connected, L - Local, S - Static, U - Per-user Static route B - BGP, HA - Home Agent, MR - Mobile Router, R - RIP H - NHRP, I1 - ISIS L1, I2 - ISIS L2, IA - ISIS interarea IS - ISIS summary, D - EIGRP, EX - EIGRP external, NM - NEMO ND - ND Default, NDp - ND Prefix, DCE - Destination, NDr - Redirect O - OSPF Intra, OI - OSPF Inter, OE1 - OSPF ext 1, OE2 - OSPF ext 2 ON1 - OSPF NSSA ext 1, ON2 - OSPF NSSA ext 2, ls - LISP site ld - LISP dyn-EID, a - Application O O O 1::/64 [110/1001] via FE80::1, Tunnel8 2::/64 [110/1001] via FE80::2, Tunnel8 7::/64 [110/1001] via FE80::7, Tunnel8 R8#Ping 1::1 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 1::1, timeout is 2 seconds: ..... Success rate is 0 percent (0/5) The ping failed. We know that on Broadcast network types the next-hop IP address is set based on the originating router, we can see that in the routing table, the next-hop IPv6 address to reach 1::/64 network is FE80::1 which is the link-local IPv6 address of R1, do we have an IPv6 nhrp mapping for that IPv6 address? CCIE R&S by Narbik Kocharians Advanced CCIE R&S Work Book 5.0 © 2015 Narbik Kocharians. All rights reserved Page 18 of 24 Let’s verify: R8#Show ipv6 nhrp FE80::1/128 via FE80::1 Tunnel8 created 00:19:33, never expire Type: static, Flags: used NBMA address: 192.1.1.1 Let’s see if we can ping the link-local IPv6 address of R1: R8#Ping fe80::1 Output Interface: Tunnel8 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to FE80::1, timeout is 2 seconds: Packet sent with a source address of FE80::8%Tunnel8 !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/2/4 ms We are successful, does this mean that we must have an IPv6 nhrp mapping for the actual IPv6 address as well? Let’s configure and verify: R8(config)#int tunn 8 R8(config-if)#ipv6 nhrp map 10::1/128 192.1.1.1 On R1: R1(config)#int tunn 1 R1(config-if)#ipv6 nhrp map 10::8/128 192.1.8.8 To verify the configuration: On R8: R8#Ping 1::1 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 1::1, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/2/4 ms OK, we can see why, the reason the pings failed initially was because the source IPv6 address of the ping CCIE R&S by Narbik Kocharians Advanced CCIE R&S Work Book 5.0 © 2015 Narbik Kocharians. All rights reserved Page 19 of 24 was the tunnel’s IPv6 address and since we did not have any mapping configured for that IPv6 address, the pings failed. Does this mean that if the same ping was sourced from the loopback 0 interface of R8, it would be successful? Let’s try this; before we try, let’s examine the routing table of R8 and R7, they must have an ipv6 nhrp mapping to the next-hop IPv6 address, let’s verify: R8#Show ipv6 route 7::7 Routing entry for 7::/64 Known via "ospf 1", distance 110, metric 1001, type intra area Route count is 1/1, share count 0 Routing paths: FE80::7, Tunnel8 Last updated 00:32:19 ago Let’s see if we have an IPv6 mapping for the next-hop IPv6 address of fe80::7: R8#Show ipv6 nhrp 10::1/128 via 10::1 Tunnel8 created 00:18:00, never expire Type: static, Flags: NBMA address: 192.1.1.1 FE80::1/128 via FE80::1 Tunnel8 created 00:43:32, never expire Type: static, Flags: used NBMA address: 192.1.1.1 No, the local router does not have an IPv6 nhrp mapping for the next-hop IPv6 address of FE80::7. Let’s configure one: R8(config)#int tunn 8 R8(config-if)#ipv6 nhrp map fe80::7/128 192.1.7.7 Now, let’s check R7: On R7: R7#Show ipv6 route 8::/64 Routing entry for 8::/64 Known via "ospf 1", distance 110, metric 1001, type intra area CCIE R&S by Narbik Kocharians Advanced CCIE R&S Work Book 5.0 © 2015 Narbik Kocharians. All rights reserved Page 20 of 24 Route count is 1/1, share count 0 Routing paths: FE80::8, Tunnel7 Last updated 00:34:43 ago R7#Show ipv6 nhrp FE80::1/128 via FE80::1 Tunnel7 created 00:46:42, never expire Type: static, Flags: used NBMA address: 192.1.1.1 Let’s configure an IPv6 nhrp mapping for the next-hop IPv6 address of fe80::8: R7(config)#int tunn 7 R7(config-if)#ipv6 nhrp map fe80::8/128 192.1.8.8 To verify the configuration: On R8: R8#Ping 7::7 Source Lo0 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 7::7, timeout is 2 seconds: Packet sent with a source address of 8::8 !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/4 ms Perfect, it worked. Let’s configure IPv6 nhrp mappings on all routers in a full mesh manner: R8(config)#int tunn 8 R8(config-if)#ipv6 nhrp map fe80::2/128 192.1.2.2 On R2: R2(config)#int tunn 2 R2(config-if)#ipv6 nhrp map fe80::7/128 192.1.7.7 R2(config-if)#ipv6 nhrp map fe80::8/128 192.1.8.8 On R7: R7(config)#int tunn 7 R7(config-if)#ipv6 nhrp map fe80::2/128 192.1.2.2 CCIE R&S by Narbik Kocharians Advanced CCIE R&S Work Book 5.0 © 2015 Narbik Kocharians. All rights reserved Page 21 of 24 To verify the configuration: On R2: R2#Ping 1::1 source Lo0 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 1::1, timeout is 2 seconds: Packet sent with a source address of 2::2 !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 4/4/4 ms R2#Ping 7::7 Source Lo0 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 7::7, timeout is 2 seconds: Packet sent with a source address of 2::2 !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 0/1/4 ms R2#Ping 8::8 Source Lo0 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 8::8, timeout is 2 seconds: Packet sent with a source address of 2::2 !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 0/2/4 ms On R1: R1#Ping 7::7 Source Lo0 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 7::7, timeout is 2 seconds: Packet sent with a source address of 1::1 !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 0/0/4 ms R1#Ping 8::8 Source Lo0 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 8::8, timeout is 2 seconds: Packet sent with a source address of 1::1 !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 0/0/4 ms CCIE R&S by Narbik Kocharians Advanced CCIE R&S Work Book 5.0 © 2015 Narbik Kocharians. All rights reserved Page 22 of 24 On R7: R7#Ping 8::8 Source Lo0 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 8::8, timeout is 2 seconds: Packet sent with a source address of 7::7 !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/1 ms NBMA networks can be configured in two ways: Point-to-point and/or Multipoint. If the network (DMVPN in this case) is configured in a Point-to-point manner, the routers have Unicast, Multicast and/or Broadcast capability. In Point-to-point networks, there can only be another router on the other end of the link, so as long as the destination network is in the routing table, we should be able to reach that destination. If the network (DMVPN in this case) is configured in a Multipoint manner, we have unicast reachability only, but Broadcast/Multicast capability can be available if it’s provided. Since in multipoint networks there can potentially be more than one router on the other end of the tunnel or link, the local router MUST have a mapping to the next-hop IPv6 address/es or else, NLRI can not be achieved. In this lab, since the spoke routers didn’t have NHRP mappings to the next-hop IPv6 address of the other endpoints, they could not reach the advertised networks and we had to configure full mesh NHRP mappings. In broadcast network types the next-hop IP address is not changed, and if the network is NBMA in nature, such as DMVPN, and it’s configured in Multipoint manner, we have to remember the following important points: Multicast capability must be provided. Spokes must have NHRP mappings to the next-hop IPv6 address to have reachability to the networks that other endpoints are advertising. The hub router should be configured as the DR, and a BDR is not needed. To achieve this, the spoke routers MUST have an OSPFv3 priority of zero so they never participate in DR election. CCIE R&S by Narbik Kocharians Advanced CCIE R&S Work Book 5.0 © 2015 Narbik Kocharians. All rights reserved Page 23 of 24 Task 3 Erase the startup configuration of the routers, the config.text and the VLAN.dat of the switches and reload them before proceeding to the next lab. CCIE R&S by Narbik Kocharians Advanced CCIE R&S Work Book 5.0 © 2015 Narbik Kocharians. All rights reserved Page 24 of 24
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