Lab 3: Autoconfiguration of IPv6 addresses

Autoconfiguration of IPv6 addresses!

Objective of the Lab

In this lab, you will learn and understand how to configure IPv6 addresses on Cisco routers using address autoconfiguration and EUI-64 addressing.

Configuring IPv6 addressing is one of the tasks you will have to do as a Cisco network administrator.

In the exam too, you may therefore be asked to configure an IPv6 address using EUI-64 Addressing Autoconfiguration.

Topology of the Lab

Below is the topology we will use for autoconfiguration of IPv6 addresses on Cisco routers.

IPv6 autoconfiguration

Task 1:

As usual, always configure the equipment names to identify them afterwards. Configure the router names as shown on the topology.

Task 2:

Configure the IP addresses on the Ethernet interfaces of R1 and R2 as shown in the topology. Next, set the Loopback interface specified in the diagram to R2.

The Gig 0/0 interface on R2 will use SLACC to get the address prefix from R1. Loopback 0 will use EUI-64 to complete the host part of the address.

Task: check autoconfiguration

Use the show command to check:

  • The IPv6 addresses configured automatically on the interfaces ;
  • The administrative status of the interfaces (up or down);
  • And finally the subnet mask.

Lab solution

Task 1: We will start with the name configurations. Here are the commands for this configuration:

On router R1


Router#configure terminal 

Router(config)#hostname R1

And on the R2 router

Router#configure terminal 
Router(config)#hostname R1

Task 2: autoconfiguration of IPv6 addresses on interfaces

Before configuring IPv6 on an interface, always enable unicast routing with the following command:

R1(config)#ipv6 unicast-routing 
R2(config)#ipv6 unicast-routing 

Configure the IPv6 address on the interface of router R1 :

R1(config)#interface gigabitEthernet 0/0

R1(config-if)#ipv6 address 2001:abcd:bcd::1/64

R1(config-if)#no shutdown 

%LINK-5-CHANGED: Interface GigabitEthernet0/0, changed state to up


On the R2 router interface, we will use IPv6 autoconfiguration and here are the commands:

R2(config)#interface gigabitEthernet 0/0

R2(config-if)#ipv6 address autoconfig 

R2(config-if)#no shutdown 
%LINK-5-CHANGED: Interface GigabitEthernet0/0, changed state to up
%LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/0, changed state to up

Configuration de l’interface Loopback 0 en utilisant donc EUI-64

R2(config-if)#ipv6 address 2001:abc::/64 eui-64 

R2(config-if)#no shutdown 

Task 3: Configuration Checks

R2#show ipv6 interface brief 
GigabitEthernet0/0 [up/up]
GigabitEthernet0/1 [administratively down/down]
GigabitEthernet0/2 [administratively down/down]
Loopback0 [up/up]
Vlan1 [administratively down/down]

Checking on Gig 0/0 interface of router R2:

R2#show ipv6 interface gigabitEthernet 0/0
GigabitEthernet0/0 is up, line protocol is up
 IPv6 is enabled, link-local address is FE80::20C:85FF:FE35:AC01
 No Virtual link-local address(es):
 Global unicast address(es):
 2001:ABCD:BCD:0:20C:85FF:FE35:AC01, subnet is 2001:ABCD:BCD::/64 [CAL/PRE]
 Joined group address(es):
 MTU is 1500 bytes
 ICMP error messages limited to one every 100 milliseconds
 ICMP redirects are enabled
 ICMP unreachables are sent
 ND DAD is enabled, number of DAD attempts: 1
 ND reachable time is 30000 milliseconds
 ND advertised reachable time is 0 (unspecified)
 ND advertised retransmit interval is 0 (unspecified)
 ND router advertisements are sent every 200 seconds
 ND router advertisements live for 1800 seconds
 ND advertised default router preference is Medium
 Hosts use stateless autoconfig for addresses.

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