IS-IS Lab 21 IPv6 Summarization

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Download Lab: VIRL | EVE-NG | GNS3


Image requirements:

Cisco IOSv (vios-adventerprisek9-m.vmdk.SPA.156-2.T)


Introduction:  
Configure IS-IS to summarize IPv6 prefixes. In this lab, you will create a loopback interface with multiple IPv6 prefixes assigned, advertise them into IS-IS topology then on the L1/L2 node configure a single summary route.


Nodes Access: 
Enable:       cisco 
Username:  cisco 
Password:   cisco 



Topology: 





Lab tasks:

1. Configure new interface loopback 1 on the router A2 with multiple /64 IPv6 prefixes.

2. Include interface loopback1 into the IS-IS process.

3. Verify that, other L1/L2 nodes receive A2's /64 prefixes.

4. Configure router A1 to summarize /64 prefixes of router A2 into the singe /60 prefix.

5. Verify summarization. Make sure that L1/L2 routers have single /60 prefix in their IPv6 routing table to reach A2's prefixes.


Lab procedure:

Step1: Configure interface loopback 1 with multiple /64 prefixes:

A2(config)#interface  loopback 1
A2(config-if)#ipv6 address 2001:DB8:1000:A000::1/64
A2(config-if)#ipv6 address 2001:DB8:1000:A001::1/64
A2(config-if)#ipv6 address 2001:DB8:1000:A002::1/64
A2(config-if)#ipv6 address 2001:DB8:1000:A003::1/64
A2(config-if)#ipv6 address 2001:DB8:1000:A004::1/64
A2(config-if)#ipv6 address 2001:DB8:1000:A005::1/64
A2(config-if)#ipv6 address 2001:DB8:1000:A006::1/64
A2(config-if)#ipv6 address 2001:DB8:1000:A007::1/64
A2(config-if)#ipv6 address 2001:DB8:1000:A008::1/64
A2(config-if)#ipv6 address 2001:DB8:1000:A009::1/64
A2(config-if)#ipv6 address 2001:DB8:1000:A00A::1/64
A2(config-if)#ipv6 address 2001:DB8:1000:A00B::1/64
A2(config-if)#ipv6 address 2001:DB8:1000:A00C::1/64
A2(config-if)#ipv6 address 2001:DB8:1000:A00E::1/64
A2(config-if)#ipv6 address 2001:DB8:1000:A00F::1/64
A2(config-if)#exit
A2(config)#



Step2: Enable interface loopback1 for IS-IS routing:

A2(config)#interface  lo1
A2(config-if)#ipv6 router isis  



Step2a: Verify local IS-IS protocol configuration:

A2#show isis protocol 
IS-IS Router: <Null Tag>
  System Id: 0000.0000.00A2.00  IS-Type: level-1
  Manual area address(es):
        49.a000
  Routing for area address(es):
        49.a000
  Interfaces supported by IS-IS:
        Loopback1 - IPv6
        GigabitEthernet0/1 - IP - IPv6
        Loopback0 - IP - IPv6
  Redistribute:
    static (on by default)
  Distance for L2 CLNS routes: 110
  RRR level: none
  Generate narrow metrics: none
  Accept narrow metrics:   none
  Generate wide metrics:   level-1-2
  Accept wide metrics:     level-1-2
A2#

The output shows that interface Loopback1 is enabled for IPv6 only.


Step2b: Check router A2's detailed database originated by the router itself:

A2#show  isis database detail A2.00-00
IS-IS Level-1 LSP A2.00-00
LSPID                 LSP Seq Num  LSP Checksum  LSP Holdtime/Rcvd      ATT/P/OL
A2.00-00            * 0x00000007   0xD617                 585/*         0/0/0
  Area Address: 49.a000
  NLPID:        0xCC 0x8E
  Hostname: A2
  Metric: 10         IS-Extended A2.01
  IP Address:   192.168.0.10
  Metric: 10         IP 10.0.0.24/30
  Metric: 10         IP 192.168.0.10/32
  IPv6 Address: 2001:DB8:B:0:1::3
  Metric: 10         IPv6 2001:DB8:B:0:1::3/128
  Metric: 10         IPv6 2001:DB8:A:0:1:1:0:18/126
  Metric: 10         IPv6 2001:DB8:1000:A000::/64
  Metric: 10         IPv6 2001:DB8:1000:A001::/64
  Metric: 10         IPv6 2001:DB8:1000:A002::/64
  Metric: 10         IPv6 2001:DB8:1000:A003::/64
  Metric: 10         IPv6 2001:DB8:1000:A004::/64
  Metric: 10         IPv6 2001:DB8:1000:A005::/64
  Metric: 10         IPv6 2001:DB8:1000:A006::/64
  Metric: 10         IPv6 2001:DB8:1000:A007::/64
  Metric: 10         IPv6 2001:DB8:1000:A008::/64
  Metric: 10         IPv6 2001:DB8:1000:A009::/64
  Metric: 10         IPv6 2001:DB8:1000:A00A::/64
  Metric: 10         IPv6 2001:DB8:1000:A00B::/64
  Metric: 10         IPv6 2001:DB8:1000:A00C::/64
  Metric: 10         IPv6 2001:DB8:1000:A00E::/64
  Metric: 10         IPv6 2001:DB8:1000:A00F::/64
A2# 

The output shows that every /64 prefix configured on the router A2' interface loopback1 is in the local database.


Step3: Access router B1's CLI and check for A2's prefixes in its detailed database:

B1#show  isis database detail A1.00-00
IS-IS Level-2 LSP A1.00-00
LSPID                 LSP Seq Num  LSP Checksum  LSP Holdtime/Rcvd      ATT/P/OL
A1.00-00              0x0000000D   0xED9C                 612/1198      0/0/0
  Auth:         Length: 17
  Area Address: 49.a000
  NLPID:        0xCC 0x8E
  Hostname: A1
  Metric: 10         IS-Extended C1.02
  IP Address:   192.168.0.2
  Metric: 10         IP 10.0.0.8/30
  Metric: 10         IP 10.0.0.24/30
  Metric: 10         IP 192.168.0.2/32
  Metric: 20         IP 192.168.0.10/32
  IPv6 Address: 2001:DB8:B:0:1::2
  Metric: 10         IPv6 2001:DB8:B:0:1::2/128
  Metric: 10         IPv6 2001:DB8:A:0:1:1:0:18/126
  Metric: 10         IPv6 2001:DB8:A:0:1:1:0:8/126
  Metric: 20         IPv6 2001:DB8:B:0:1::3/128
  Metric: 20         IPv6 2001:DB8:1000:A00F::/64
  Metric: 20         IPv6 2001:DB8:1000:A00E::/64
  Metric: 20         IPv6 2001:DB8:1000:A00C::/64
  Metric: 20         IPv6 2001:DB8:1000:A00B::/64
  Metric: 20         IPv6 2001:DB8:1000:A00A::/64
  Metric: 20         IPv6 2001:DB8:1000:A009::/64
  Metric: 20         IPv6 2001:DB8:1000:A008::/64
  Metric: 20         IPv6 2001:DB8:1000:A007::/64
  Metric: 20         IPv6 2001:DB8:1000:A006::/64
  Metric: 20         IPv6 2001:DB8:1000:A005::/64
  Metric: 20         IPv6 2001:DB8:1000:A004::/64
  Metric: 20         IPv6 2001:DB8:1000:A003::/64
  Metric: 20         IPv6 2001:DB8:1000:A002::/64
  Metric: 20         IPv6 2001:DB8:1000:A001::/64
  Metric: 20         IPv6 2001:DB8:1000:A000::/64
B1#

Repeat this step for the rest of the L1/L2 nodes and core routers.


Step3a: Confirm connectivity to any IPv6 address of A2's loopback1 interface from any L1/L2 router:

B1#ping 2001:DB8:1000:A000::1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 2001:DB8:1000:A000::1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 3/9/32 ms
B1#


Step4: Implement summarization on the router A1, since node A1 is the only L1/L2 router in the area A000 summary prefix has to be placed on this router:

A1(config)#router  isis
A1(config-router)#address-family ipv6
A1(config-router-af)#summary-prefix 2001:DB8:1000:A000::/60
A1(config-router-af)#end



Step4a: Verify that router A1 perform summarization with these following commands:

A1#show  ipv6 protocols IPv6 Routing Protocol is "connected"
IPv6 Routing Protocol is "application"
IPv6 Routing Protocol is "ND"
IPv6 Routing Protocol is "isis"
  Interfaces:
    Loopback0
    GigabitEthernet0/1
    GigabitEthernet0/2
  Redistribution:
    None
  Address Summarization:
    L2: 2001:DB8:1000:A000::/60  advertised with metric 20

A1#show  isis database detail A1.00-00 level-2 
IS-IS Level-2 LSP A1.00-00
LSPID                 LSP Seq Num  LSP Checksum  LSP Holdtime/Rcvd      ATT/P/OL
A1.00-00            * 0x00000030   0x58D9                1049/*         0/0/0
  Auth:         Length: 17
  Area Address: 49.a000
  NLPID:        0xCC 0x8E
  Hostname: A1
  Metric: 10         IS-Extended C1.02
  IP Address:   192.168.0.2
  Metric: 10         IP 10.0.0.8/30
  Metric: 10         IP 10.0.0.24/30
  Metric: 10         IP 192.168.0.2/32
  Metric: 20         IP 192.168.0.10/32
  IPv6 Address: 2001:DB8:B:0:1::2
  Metric: 10         IPv6 2001:DB8:B:0:1::2/128
  Metric: 10         IPv6 2001:DB8:A:0:1:1:0:18/126
  Metric: 10         IPv6 2001:DB8:A:0:1:1:0:8/126
  Metric: 20         IPv6 2001:DB8:B:0:1::3/128
  Metric: 20         IPv6 2001:DB8:1000:A000::/60
A1#

Both of these show commands confirm that A1 is advertising only /60 prefix to the core router C1.

Step5: Verify summarization of A2's prefixes from other L1/L2 routers point of view:

D1#show  isis database detail A1.00-00
IS-IS Level-2 LSP A1.00-00
LSPID                 LSP Seq Num  LSP Checksum  LSP Holdtime/Rcvd      ATT/P/OL
A1.00-00              0x00000030   0x58D9                 781/1198      0/0/0
  Auth:         Length: 17
  Area Address: 49.a000
  NLPID:        0xCC 0x8E
  Hostname: A1
  Metric: 10         IS-Extended C1.02
  IP Address:   192.168.0.2
  Metric: 10         IP 10.0.0.8/30
  Metric: 10         IP 10.0.0.24/30
  Metric: 10         IP 192.168.0.2/32
  Metric: 20         IP 192.168.0.10/32
  IPv6 Address: 2001:DB8:B:0:1::2
  Metric: 10         IPv6 2001:DB8:B:0:1::2/128
  Metric: 10         IPv6 2001:DB8:A:0:1:1:0:18/126
  Metric: 10         IPv6 2001:DB8:A:0:1:1:0:8/126
  Metric: 20         IPv6 2001:DB8:B:0:1::3/128
  Metric: 20         IPv6 2001:DB8:1000:A000::/60

Router D1 has only the single /60 prefix to reach subnets of A2's loopback1 interface. Other L1/L2 routers should have the same outcome.


Step5a: Verify connectivity to first and last prefixes of router A2's loopback1 interface from any L1 only nodes:

E2#ping 2001:DB8:1000:A000::1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 2001:DB8:1000:A000::1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 6/9/19 ms
E2#

E2#ping 2001:DB8:1000:A00F::1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 2001:DB8:1000:A00F::1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 5/5/7 ms

Successful ping confirms that summarization works as intended.

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