Juniper: Configuring IPv6 address on a interface

 IP version 6 (IPv6) is the latest version of IP. IPv6 builds upon the functionality of IPv4, providing improvements to addressing, configuration and maintenance, and security. Juniper Networks is focused on helping service provider and enterprise customers deploy IPv6 in ways that improve current networks.

IPv6 Address Format

IPv6 addresses consist of eight hexadecimal groups. Each hexadecimal group, separated by a colon (:), consists of a 16-bit hexadecimal value. The following is an example of the IPv6 format:
xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx

A group of xxxx represents the 16-bit hexadecimal value. Each individual x represents a 4-bit hexadecimal value. The following is an example of a possible IPv6 address:

4FDE:0000:0000:0002:0022:F376:FF3B:AB3F

The first sixty four bits (4FDE:0000:0000:0002) are network bits, the remaining ones are the host's interface identifier (host bits). The network portion is provided by an ISP or by the registry (ARIN or RIPE).
The length of the prefix depends on the size of your organization:

• Registries are assigned /23.
• ISPs are assigned /32.
• Sites are assigned /48.

To configure ipv6 address on an interface in juniper routers follow these instructions and commands

Note: In junos ipv6 is enabled as soon as one interface is configured for ipv6

1.Enter into configuration mode

2. Enter the [edit interfaces] mode to configure the ipv6 address of so-0/0/0 interface of Router(R1)

3. Confirm the configuration by entering the show command from configuration mode

On router (R1)

user@R1>configure
[Edit]
user@R1#edit interfaces so-0/0/0
[edit interfaces so-0/0/0]
user@R1#set unit 0 family inet6 address 2001:cb8:1::1/64
[edit interfaces so-0/0/0]
user@R1#exit
[edit]
user@R1#show

For all ipv6 and other juniper simulator labs please check this

Available practice labs for juniper 

The Cert-Ex™ Juniper Network Simulator w/designer software is a tool enables candidates to work on Juniper router and switches in a stand alone virtual lab environment. Several labs have been made available for practice in the lab manual. Both Command Line Interface (CLI) mode and Graphical User Interface (GUI) mode are available. Domains covered in the labs include 

1. Basic IP address configuration of routers and switches

2. RIP, OSPF, DHCP, NAT, Firewall configurations

3. VLAN, VTP configurations

3. STP configuration and troubleshooting