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Unable to remove IPv6 from physical interface of ProxySG/ISG

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Article ID: 244342

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Updated On:

Products

ISG Proxy ProxySG Software - SGOS

Issue/Introduction

Unable to remove IPv6 from physical interface of ProxySG/ISG 

Cause

IPv6 addresses starting with 'fe80::' are 'link local' addresses which are automatically generated (by default). These addresses you CANNOT be deleted.

Link local is an IPv6 'feature' that allows devices to communicate with one another without the need for DHCP[v6] or some type of IP configuration tool. This is nothing but just a prefix (fe80:: following by the interfaces MAC address). Typically this is on by default if you allow IPv6 (which the ProxySG do by default – that is allow IPv6), not specific to SGOS.

IPv4 has something similar RFC-3927 -> Dynamic Configuration of IPv4 Link-Local.. Microsoft uses it if you connect to a network with no DHCP; Windows still gives you an address.. usually starting with 169.254.x.x/16

Resolution

However there are two configuration cli commands to control link local addresses:

Disables all link local addresses on all interfaces
(config)ipv6 auto-linklocal disable

Disables link local addresses for a particular interface e.g
(config interface 0:0)ipv6 auto-linklocal disable

Removing the above would remove the link local IPv6 address