[VRRP] RFC 5798 - ipv6 link-local configuration

Alexey Razuvaev <alxrazuvaev@gmail.com> Thu, 17 May 2012 14:11 UTC

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From: Alexey Razuvaev <alxrazuvaev@gmail.com>
Date: Thu, 17 May 2012 10:10:49 -0400
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Subject: [VRRP] RFC 5798 - ipv6 link-local configuration
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VRRPv3 for IPv6 specifies that the first address should be a link-local
address. If that is configured by an operator and not generated by
software, how do we make sure that there are no collisions with existing
link local addresses? Since the protocol spec does not mention any
link-local address range dedicated to VRRP, how do
current implementations make sure that it doesn't collide with anyone else
on the network? I understand that IPv4 has similar issues, but in IPv4 case
the network would be statically configured, unlike in IPv6 case where
link-local addresses are generated from MAC.

Additionally what is the reasoning behind not allowing to use Virtual MAC
address to generate link-local address? It seems like it would simplify the
set up, but I think I am missing some crucial detail.

Also, if I were to allow global IPv6 to be configured for virtual router, I
would have to force the operator to also configure a link-local address,