FastIron Configuration Guide

07.4.00a

Part Number: 53-1002494-02

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IPv6 addressing

IPv4 is limited because of the 32-bit addressing format, which cannot satisfy potential increases in the number of users, geographical needs, and emerging applications. To address this limitation, IPv6 introduces a new 128-bit addressing format.

An IPv6 address is composed of 8 fields of 16-bit hexadecimal values separated by colons (:). Figure 33 shows the IPv6 address format.

Figure 33 IPv6 address format

As shown in Figure 33, HHHH is a 16-bit hexadecimal value, while H is a 4-bit hexadecimal value.The following is an example of an IPv6 address.

2001:0000:0000:0200:002D:D0FF:FE48:4672

Note that this IPv6 address includes hexadecimal fields of zeros. To make the address less cumbersome, you can do the following:

•	Omit the leading zeros; for example, 2001:0:0:200:2D:D0FF:FE48:4672.

•	Compress the successive groups of zeros at the beginning, middle, or end of an IPv6 address to two colons (::) once per address; for example, 2001::200:2D:D0FF:FE48:4672.

When specifying an IPv6 address in a command syntax, keep the following in mind:

•	You can use the two colons (::) only once in the address to represent the longest successive hexadecimal fields of zeros

•	The hexadecimal letters in IPv6 addresses are not case-sensitive

As shown in Figure 33, the IPv6 network prefix is composed of the left-most bits of the address. As with an IPv4 address, you can specify the IPv6 prefix using the <prefix>/<prefix-length> format, where the following applies.

The <prefix> parameter is specified as 16-bit hexadecimal values separated by a colon.

The <prefix-length> parameter is specified as a decimal value that indicates the left-most bits of the IPv6 address.

The following is an example of an IPv6 prefix.

2001:FF08:49EA:D088::/64

Enabling and disabling IPv6

IPv6 is enabled by default for Brocade devices that support it. If desired, you can disable IPv6 on a global basis on an device by entering the following command at the Global CONFIG level of the CLI.

Brocade(config)#no ipv6 enable

 

Syntax:

no ipv6 enable

To re-enable IPv6 after it has been disabled, enter the ipv6 enable command.