Technical Tip: How to configure a secondary IPv6 address on an interface

[pdudhatra]

Description
This article describes how to configure a secondary IPv6 on an interface.

Solution
The following steps can be used to configure a secondary IPv6 address on an interface.

1) Enable the secondary IP option.

- From GUI, go to System -> Interfaces -> Interface name.

- from CLI.

# config system interface
    edit <interface>
        set secondary-IP enable
    end

2) Configure the secondary IP from CLI.

# config system interface
    edit <interface>
        # config ipv6
        # config ip6-extra-addr
            edit <IP/Prefix>
        end
    end
end

Note.
Configuring secondary IPv6 address on an interface will be available only via CLI.

Additional Note.
If ip6-mode is set to 'DHCP', it is not possible to configure secondary IPv6 on that interface.
It does not allow to configure 'ip6-extra-addr' with 'ip6-mode' set to 'DHCP'.

ALPHA_GATE (ipv6) # set ip6-mode dhcp
ALPHA_GATE (ipv6) # config
<Enter>

The 'ip6-extra-addr' can only be configured if the 'ip6-mode' is set to 'static'.   

ALPHA_GATE (ipv6) # set ip6-mode static
ALPHA_GATE (ipv6) # config ip6-extra-addr
ALPHA_GATE (ip6-extra-addr) # edit 2001:0db8:85a3:0000:0000:8a2e:0370:7334
new entry '2001:0db8:85a3:0000:0000:8a2e:0370:7334' added